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CIHM/ICMH 

Microfiche 

Series. 


CIHM/ICMH 
Collection  de 
microfiches. 


Canadian  Institute  for  Historicai  IVIicroreproductions  /  institut  Canadian  de  microrepror^uctions  historiques 


5. 


Technical  and  Bibliographic  Notes/Notes  techniques  et  bibliographiques 


The 
toth 


The  Institute  has  attempted  to  obtain  the  best 
original  copy  available  for  filming.  Features  of  this 
copy  which  may  be  bibliographicaily  unique, 
which  may  alter  any  of  the  images  in  the 
reproduction,  or  which  may  significantly  change 
the  usual  method  of  filming,  are  checlced  below. 


□    Coloured  covers/ 
Couverture  de  couleur 


I     I    Covers  damaged/ 


D 


D 
D 


D 


Couverture  endommagAe 


Covers  restored  and/or  laminated/ 
Couverture  restaur^  et/ou  pellicui^e 


I     I    Cover  titie  missing/ 


Le  titre  de  couverture  manque 


I     I   Coloured  maps/ 


Cartes  g6ographiques  en  couleur 


□   Coloured  ink  (i.e.  other  than  blue  or  blacic)/ 
Encre  de  couleur  (i.e.  autre  que  bleue  ou  noire) 

I     I   Coloured  plates  and/or  illustrations/ 


D 


Planches  et/ou  illustrations  en  couleur 


Bound  with  other  material/ 
Reli4  avec  d'autres  documents 


Tight  binding  may  cause  shadows  or  distortion 
along  interior  margin/ 

La  re  Mure  serrde  peut  causer  de  I'ombre  ou  de  la 
distortion  le  long  de  la  marge  IntArleure 

Blank  leaves  added  during  restoration  may 
appear  within  the  text.  Whenever  possible,  these 
have  been  omitted  from  filming/ 
11  se  peut  que  certaines  pages  blanches  ajouties 
lors  d'une  restauration  apparaissent  dans  le  texte, 
mais,  lorsque  cela  6tait  possible,  ces  pages  n'ont 
pas  6t6  filmies. 

Additional  comments:/ 
Commentalres  suppl^mentaires: 


L'Institut  a  microfilm^  le  meilleur  exemplaire 
qu'il  lul  a  At6  possible  de  se  procurer.  Les  details 
de  cet  exemplaire  qui  sont  peut-Atre  uniques  du 
point  de  vue  bibliographique,  qui  peuvent  modifier 
une  image  reprodulte,  ou  qui  peuvent  exiger  une 
modification  dans  la  methods  normale  de  filmage 
sont  indiquAs  ci-dessous. 


I      I   Coloured  pages/ 


0 


Pages  de  couleur 

Pages  damaged/ 
Pages  endommag6es 

Pages  restored  and/oi 

Pages  restauries  et/ou  pelliculies 

Pages  discoloured,  stained  or  foxe« 
Pages  d6color6es,  tacheties  ou  piquies 

Pages  detached/ 
Pages  d6tach6e8 

Showthrough/ 
Transparence 

Quality  of  prir 

Qualiti  Inigale  de  I'impression 

Includes  supplementary  materii 
Comprend  du  materiel  suppKmentaire 

Only  edition  available/ 
Seuie  Mition  disponlble 


I — I  Pages  damaged/ 

I — I  Pages  restored  and/or  laminated/ 

[T~7  Pages  discoloured,  stained  or  foxed/ 

r~~1  Pages  detached/ 

[771  Showthrough/ 

I      I  Quality  of  print  varies/ 

I      I  Includes  supplementary  material/ 

I      I  Only  edition  available/ 


The 
posa 
of  tr 
filmi 


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the  I 
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othe 
first 
sion, 
or  ill 


The 
shall 
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whic 

Map 
diffe 
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requ 
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Pages  wholly  or  partially  obscured  by  errata 
slips,  tissues,  etc.,  have  been  ref limed  to 
ensure  the  best  possible  image/ 
Les  pages  totalement  ou  partlellement 
obscurcles  par  un  feuillet  d'errata,  une  pelure. 
etc.,  ont  4t6  filmtes  A  nouveau  de  faqon  A 
obtenir  la  meilleure  image  possible. 


This  item  Is  filmed  at  the  reduction  ratio  checked  below/ 

Ce  document  est  fllmA  au  taux  de  reduction  indiqu*  ci-dessous. 


10X 

14X 

18X 

22X 

26X 

aox 

y 

D 

12X 


16X 


20X 


24X 


28X 


32X 


The  copy  filmed  here  hes  been  reproduced  thenke 
to  the  generoeity  of: 


Lferary, 

GaologlMl  Surwy  of  Canada 


L'exempleire  filmi  fut  reproduit  grAce  A  la 
gAnirositA  de: 

BibliotMqua, 

CommMon  Gtologiqua  du  Canada 


The  imagee  appeering  here  are  the  best  quality 
possible  considering  the  condition  end  legibility 
of  the  original  copy  and  In  keeping  with  the 
filming  contract  speciflcetions. 


Les  images  suivantes  ont  M  reproduitas  avec  le 
plus  grand  soin.  compte  tenu  de  la  condition  et 
de  la  nettet*  de  l'exempleire  film*,  et  en 
conformity  avec  les  conditions  du  contrat  de 
filmage. 


Original  copies  in  printed  paper  covers  are  filmed 
beginning  with  the  front  cover  end  ending  on 
the  last  page  with  a  printed  or  Ulustrated  impres- 
sion, or  the  back  cover  when  appropriate.  All 
other  original  copies  are  filmed  beginning  on  the 
first  poge  with  a  printed  or  illustrsted  impres- 
sion, end  ending  on  the  last  page  with  a  printed 
or  illustreted  impression. 


Les  exemplaires  originaux  dont  la  couverture  en 
papier  est  ImprimAe  sont  filmte  en  commenqant 
par  le  premier  plat  et  en  terminant  soit  par  la 
dernfAre  page  qui  comporte  une  empreinte 
d'impression  ou  d'iilustratlon.  soit  par  le  second 
plat,  salon  le  cas.  Tous  las  autres  exemplaires 
origineux  sont  filmis  en  commenqant  par  la 
premlAre  page  qui  comporte  une  emp^iinte 
d'impression  ou  d'iilustratlon  et  en  tei  minant  par 
la  darnlAre  page  qui  comporte  une  telle 
en  oreinte. 


The  last  recorded  frame  on  each  microfiche 
shall  contain  the  symbol  — <»>  (meaning  "CON- 
TINUED "),  or  the  symbol  V  (meaning  "END  "), 
whichever  applies. 


Un  des  symboles  suivants  apparaftra  sur  la 
dernlAre  image  de  cheque  microfiche,  selon  le 
cas:  le  symbols  —^  signifie  "A  SUIVRE",  le 
symbols  V  signifie  "FIN". 


Maps,  platee.  charts,  etc..  may  be  filmed  at 
different  reduction  ratios.  Those  too  large  to  be 
entirely  included  in  one  exposure  are  filmed 
beginning  in  the  upper  left  hand  corner,  left  to 
right  and  top  to  bottom,  as  many  frames  as 
required.  The  following  diagrams  illustrate  the 
method: 


Les  cartes,  plenches,  tableaux,  etc.,  peuvent  Atre 
fiimts  A  des  taux  de  reduction  diffArents. 
Lorsque  le  document  est  trop  grand  pour  Atre 
reproduit  en  un  seul  clichA,  11  est  f  ilmA  A  partir 
de  Tangle  supArieur  gauche,  de  gauche  d  droite, 
et  de  haut  en  bas,  en  prenant  le  nombre 
d'images  n^cessaire.  Les  diagrammes  suivants 
illustrent  la  mtthode. 


1 

2 

3 

32X 


1 

2 

3 

4 

5 

6 

( 


MEMOIRS 


OF  THE 


MTTSFJTM     OF     TOMPAR  ATTVT?     ZOOLOGY 


Compliments  of  FRANK  SPRINGER 

and 

Alexander  Agassiz. 


CAMBRIDGE.   U.S.A. 
PRINTED    FOR   THE   MUSEUM. 

1897. 


I 


MEMOIRS 


OF  THE 


MUSEUM    OF    COMPARATIVE    ZOOLOGY 


AT 


HARVARD  COLLEGE. 


VOL.  XX. 


CAMBRIDGE,   U.S.A. 
PRINTED    FOR   THE   MUSEUM. 

1897. 


«'■;■ 
>)  1 


(" 


UmrmflTTr  Press: 
JoBM  Wilson  and  Son,  Caubridoe,  U.  S.  A. 


,"-'Siv'**'-S"^-''W 


I 


CONTENTS. 


THE    NORTH    AMERICAN    CRINOIDEA   CAMERATA.     By  Charles  Wachsmutii  and 
Frank  Sprinobr.    Chapter  I.-IX.    Page  1-369. 


A-OVN 


£[ttmotrit  of  t^t  Pnatum  of  Comparattbt  jSooIooq 

AT   HARVARD   OOLLEQB. 
Vol.  XX. 


THE  NORTH  AMERICAN 


CRINOIDEA    CAMERATA. 


Bv  CHARLES  WACIISMUTH  and  FRANK  SPRINGER. 


IN  TWO  VOLUMES  WITH  EIGHTY-THREE  PLATES. 


/ 


Vol.  I. 


CAMBRIDGE,  U.S.A.: 

^tinttti  for  t&e  iHugeunu 

Mat,  1897. 


1 


Co  tl)e  illemorp 


or 


LOUIS    AGASSIZ, 


TO  WnOSE  INFLUENCK  A.S  TEACIIKII,    KXI'OL'NDEK,   ASH    INVESTIGATOR,    NATVRAL 
IIISTOIIY    IN    AMERICA    l«   80    DEEPLY    INDEIITEP, 

AND  WHO  FIU8T  ISSI'IIIKU  AND  ENlornAOED  US  IN  OCR  EAIIUEU  STUDIES, 

IS  ORATErCLLY  DEDICATED  BY 

CIIAHLES   WACII9MUTH. 
FUANK  SrUIXOEK. 


m 


I 


.V.S^'SfeSi'S*  '^^ 


NOTE. 


J 


The  Manuscript  of  this  work  in  its  present  form  was  received  at  Cam- 
bridge for  publication  September  1,  1894.  Although  in  press  ever  since 
then,  no  part  of  it  has  been  published  until  now,  and  the  date  of  the  work, 
for  bibliographic  purposes,  will  be  that  which  appears  on  the  title-pnge. 
During  the  long  time  that  has  been  consumed  in  the  printing  of  the  plates 
and  letter-press  work  since  the  completion  of  the  text,  many  new  species 
of  Crinoids  have  been  described  by  American  authors,  among  which  some 
of  those  herein  mentioned  as  new  are  included,  and  thus  anticipated.  No 
attempt  has  been  made  to  cover  these  cases  by  modifying  the  text,  nor 
have  any  questions  arising  upon  publications  appearing  subsequent  to  the 
above  date  been  considered  here.  In  a  work  of  this  size  while  in  press 
changes  could  not  be  made  to  keep  pace  with  current  researches,  and  the 
date  of  delivery  of  the  Manuscript  for  publication  was  therefore  taken  by 
the  authors  as  final,  so  far  as  they  were  concerned. 

It  is  a  source  of  extreme  regret  that  my  learned  colleague  and  long-time 
friend.  Dr.  Charles  Wachsmuth,  did  not  live  to  see  the  publication  of  this 
Monograph,  to  which  he  had  devoted  so  many  years  of  assiduous  labor. 
Never  a  robust  or  healthy  man,  his  last  few  years  were  almost  a  continual 
struggle  against  disease.  His  strength  gradually  failed,  and  he  passed  away 
on  February  7,  1896,  at  the  age  of  sixty-seven  years. 

Dr.  Wachsmuth  was  a  native  of  Hanover,  Germany.  He  came  to  the 
United  States  in  1852,  and  soon  after  engaged  in  mercantile  piu'suits  at 
Burlington,  Iowa,  which  became  his  permanent  home.  Failing  health  in 
time  compelled  him  to  relinquish  business,  and  for  the  last  thirty  years  he 
applied  himself  to  the  study  of  the  Crinoids,  first  as  a  recreation  and  to 
secure  outdoor  exercise,  and  afterwards  as  his  life  work,  with  all  the  ardor 
of  a  scientific  devotee.  His  keen  powers  of  observation,  sagacious  judgment, 
and  indefatigable  energy  have  left  their  impress  upon  the  works  which  have 
been  brought  out  by  us.  While  his  death  is  a  loss  to  Science  not  easily 
repaired,  it  is  to  none  so  great  —  aside  from  his  family  —  as  to  the  friend 
with  whom  he  had  worked  in  pleasant  collaboration  for  so  many  years.  It 
is  with  a  melancholy  pleasure  that  I  avail  myself  of  the  opportunity  aflbrdod 
by  the  appearance  of  his  last  work  to  pay  this  slight  tribute  to  his  memory. 


FRANK  SPRINGER. 


Lau  Vegas,  New  Mexico,  1897. 


,:3i»r«'''pv; 


INTRODUCTION. 


The  present  work  is  the  outgrowth  of  studies  begun  over  twenty  years 
ago  under  tlie  encouragement  of  Prof.  Louis  Agassiz,  and  prosecuted  con- 
tinuously ever  since.  During  that  time,  we  made  two  very  large  crinoidnl 
collections,  of  which  the  original  one,  in  1873,  was  secured  by  Prof.  Agassiz, 
for  the  Museum  of  Comparative  Zoology,  Upon  this  collection  one  of  the 
writers,  while  an  assistant  at  the  Museum,  laid  the  foundation  of  the  present 
work.  Since  1877  the  investigations  were  conducted  by  us  jointly,  and 
during  that  time  we  have  built  up  together  the  extensive  collection  which 
is  known  aa  the  collection  of  Wachsmuth  and  Springer.  The  advantage  of 
residing,  for  a  time  both  of  us,  at  Burlington,  a  locality  so  well  known  for 
the  wealth  of  its  crinoidal  remains,  gave  us  excellent  opportunities  to  study 
the  Crinoids  in  all  f-tages  of  preservation,  and  being  in  the  field  ourselves,  we 
could  pick  up  such  material  as  would  help  us  in  the  study  of  minute  details. 

Since  the  publication  of  our  first  paper  on  the  Crinoids,  it  has  been  our 
aim  to  direct  our  special  attention  to  studying  the  morphology  of  the  vari- 
ous groups  as  they  appeared  to  us,  with  a  view  to  future  classification,  and 
to  revise  the  work  of  the  previous  writers.  The  various  classifications  which 
had  been  proposed  were  not  based  upon  strictly  morphological  principles,  and 
in  many  cases  widely  distinct  forms  were  placed  together  in  the  same  group. 

It  early  became  evident  to  us  that  we  could  not  hope  to  gain  a  correct 
understanding  of  the  fossil  forms  except  by  studying  their  living  represen- 
tatives. The  publication  of  Carpenter's  two  Challenger  Reports,  and  De 
Loriol's  important  Monograph  on  the  Mesozoic  and  later  Crinoids  of  France, 
opened  to  the  working  paiasontologist  a  new  field  of  research,  and  enabled 
him  to  study  the  relations  between  palaeozoic  and  neozoic  Crinoids,  which 
had  been  altogether  misunderstood.  It  had  been  the  general  opinion,  ever 
since  the  time  of  Johannes  Miiller,  that  all  paleozoic  forms  were  widely 
distinct  from  the  later  ones,  a  view  also  held  by  us  until  1890. 

Before  the  publication  of  the  first  Challenger  Report,  the  attention  of 
palaeontologists  had  been  directed  almost  exclusively  to  the  structure  of  the 
dorsal  or  abactinal  side  of  the  calyx;  that  of  the  ventral  side  had  been  very 
much  neglected,  and  scarcely  any  attempt  had  been  made  to  homologize  the 


2 


INTRODUCTION. 


plates  of  the  tegmen  in  the  different  groups.  The  first  attempt  in  this 
direction  wns  made  by  Wachsmuth  in  1877,  and  the  subject  was  taken  up 
again  in  our  Revision  of  1879.  Dr.  P.  Herbert  Carpenter  discussed  the 
question  more  elaborately  in  1884,  when  it  became  manifest  that  our  views 
differed  radically  upon  several  important  points,  and  especially  as  to  the 
identification  of  the  oral  plates.  The  progress  of  our  studies  on  this  and 
other  questions  was  published  from  time  to  time  in  the  Revision,  and  in 
short  papers.  This  was  done  for  the  double  purpose  of  making  known  the 
results  of  our  own  studies,  and  of  stimulating  inquiry  by  others  upon  points 
that  were  still  obscure. 

Whatever  may  he  the  merits  or  demerits  of  the  Revision —  and  that  the 
latter  are  many  and  serious  none  are  better  aware  than  we  —  it  accom- 
plished one  of  its  purposes.  It  induced  research  and  provoked  discussion 
upon  new  lines  and  with  an  activity  unprecedented  in  this  field.  The 
contributions  to  the  knowledge  of  the  subject,  resulting  directly  from  these 
controversies,  have  been  of  incalculable  value  to  us,  and  none  the  less  so 
because  some  of  our  own  theories  have  been  from  time  to  time  exploded. 
As  the  most  important  result,  it  has  now  become  clear  that  the  Crinoids 
were  most  intimately  connected  from  the  Silurian  down  to  the  present 
time,  and  that  only  the  Camerata  —  a  highly  specialized  type  —  became 
extinct  at  the  close  of  the  Carboniferous.  It  was  not  until  this  fact  was 
realized  that  the  way  was  opened  to  a  better  understanding  of  the  whole 
Crinoid  group,  in  which,  as  so  often  found  in  Nature,  the  simpler  forms 
persisted,  and.  led  down  to  present  types.  Although  it  seems  jolain  enough 
now,  it  was  only  by  slow  steps,  and  after  long  and  patient  research,  that 
this  result  was  reached. 

After  a  large  amount  of  preliminary  work  had  been  done,  we  proceeded 
to  prepare  for  publication  in  permanent  form  such  part  of  it  as  we  could 
reasonably  hope  to  finish,  and  to  that  end  we  began  the  preporation  of  the 
illustrations  in  1887.  The  work  has  grown  upon  our  hands  to  such  an 
extent  that  we  found  it  necessary  to  limit  it  to  the  Camerata,  the  largest 
and  most  remarkable  group  among  Palosozoic  Crinoids.  Thus  limited,  we 
could  hope  to  give  a  reasonably  full  account  of  this  group,  and  in  connec- 
tion with  discussion  of  the  morphological  and  systematic  relations  of  the 
other  groups,  to  give  some  accoimt  of  the  Crinoids  generally. 

The  most  of  the  drawings  were  made  under  our  personal  supervision  in 
our  Museum  at  Burlington ;  a  few  were  made  in  Washington.     Thirty-five 


1 


"m^ 


INTRODUCTION. 


of  the  jiliites  were  drawn  by  Dr.  Cliarles  R.  Keyes,  tlio  present  State  geolo- 
gist of  Missouri ;  thirty-three  by  Mr.  A.  M.  Westergren,  so  well  known  for 
his  drawings  for  Lovon'a  great  work  on  the  Echinoids ;  the  reniainin"- 
twelve  by  Mr.  John  R.  Ridgway,  artist  for  the  United  States  Geological 
Survey.  The  execution  of  the  plates  occupied  about  six  years,  and  we 
avail  ourselves  of  this  opportunity  to  express  our  thanks  to  all  of  these 
gentlemen  for  the  fidelity  and  earnestness  with  which  they  performed 
their  work. 

When  the  work  began  to  assume  a  definite  shape,  Mr.  A.  Agassiz,  on 
being  made  acquainted  with  the  extent  to  which  it  had  progressed,  kindly 
offered  to  undertake  its  publication  as  a  part  of  the  Memoirs  of  the  Museum 
of  Comparative  Zoology  at  Harvard  College.  No  words  of  thanks  would 
at  all  express  our  sense  of  the  obligation  under  which  this  has  laid  us,  not 
merely  for  the  facility  of  publication  through  so  desirable  a  medium,  but 
for  the  mark  of  appreciation  whicli  this  offer  implies.  If  the  work  shall  be 
found  sufficiently  useful  to  science  to  merit,  even  in  a  small  degree,  the 
indorsement  thus  given,  we  shall  deem  it  the  best  return  we  can  make. 

During  the  studies  that  led  up  to  this  Monograph,  we  enjoyed  the  privi- 
lege of  continued  communication  with  our  lamented  friend,  P.  Herbert 
Carpenter,  up  to  the  time  of  his  decease.  We  had  some  energetic  con- 
troversies in  print,  and  a  far  greater  number  in  private  correspondence  that 
never  saw  the  light.  To  his  incisive  and  suggestive  mind  is  due  the  over- 
throw of  more  than  one  promising  but  untenable  theory ;  and  we  take  a 
melancholy  pleasure  in  recording  here  our  appreciation  of  his  high  attain- 
ments, and  our  sense  of  the  great  loss  which  Science  has  suffered  through 
his  untimely  death. 

It  has  been  our  purpose  to  give  descriptions  of  all  American  species  of 
the  Camerata  known  up  to  this  date,  and  those  that  coidd  be  recognized 
have  been  described  anew,  with  the  aids  derived  from  the  material  brouo-ht 
to  light  since  the  original  descriptions  were  made.  Many  of  the  species 
wen  defined  from  very  imperfect  specimens,  and  often  without  illustrations. 
In  the  latter  cases  we  have,  when  practicable,  figured  the  typo  specimen, 
and  when  necessary  and  possible  have  given  figures  of  additional  specimens. 

During  the  preparation  of  the  work  we  have  had  access  to  most  of  the 
type  specimens  in  the  United  States  and  Canada,  which  were  placed  in  our 
hands  for  comparison,  study,  and  illustration.  A  few  only  of  Prof.  Hall's 
types  in  the  New  York  State  Cabinet  of  Natural  History  at  Albany,  and 
some  of  S.  A.  Miller's  later  species,  we  were  unable  to  procure. 


4  INTRODUCTION. 

Not  the  least  of  the  pleasure  we  find  in  bringing  our  work  to  a  conclusion, 
is  the  opportunity  it  affords  us  of  acknowledging  our  obligations  to  the  men 
of  science  and  collectors  of  America,  for  their  liberality  and  personal  con- 
fidence shown  to  us,  by  placing  in  our  hands  —  often  for  indefinite  periods 
—  original,  unique,  and  priceless  collections,  without  the  use  of  which  this 
work  would  have  been  impossible.  It  would  be  difficult  to  express  in  fitting  ' 
terms  of  acknowledgment  the  full  measure  of  our  indebtedness  to  them,  and 
we  can  only  venture  the  hope  that  they  may  find  in  the  work  itself  some 
small  return  for  the  valuable  contributions  they  have  made  toward  it. 

To  Mr.  Agassiz  we  owe  a  lasting  debt  of  gratitude:  first  of  all  for  hia 
personal  encouragement  and  valuable  counsel,  and  next  for  the  use  of  the 
magnificent  collection  of  the  Museum  of  Comparative  Zoology.  This  has 
been  placed  at  our  disposal  without  restriction,  not  only  for  examination  at 
Cambridge,  but  for  removal  to  Burlington  of  all  specimens  we  desired,  with 
liberty  to  use  them  as  if  they  were  our  own.  Only  those  who  are  acquainted 
with  the  character  and  value  of  this  unrivalled  collection  can  appreciate  our 
obligation  for  such  a  use  of  it.  It  contains  the  original  collection  of  De 
Koninck,  of  the  Belgian  Carboniferous  Crinoids,  and  the  Schultze  collection 
from  the  Devonian  of  the  Eifel,  —  by  far  the  finest  collections  that  have 
ever  been  made  of  the  rare  Crinoids  of  those  interesting  localities.  There 
are  also  the  collections  made  by  Hon.  B.  J.  Hall,  Prof.  W.  H.  Barris,  and 
the  original  collection  of  Wachsmuth,  all  from  the  Burlington  limestone, 
which  include  the  types  of  a  large  number  of  the  species  described  by  Hall, 
White,  and  Meek  and  Worthen.  In  addition  to  these  is  the  fine  collection 
made  by  C.  B.  Dyer,  from  the  Hudson  River  group,  of  Cincinnati,  con- 
taining many  typos  of  species  described  by  Meek  in  the  Ohio  report,  besides 
most  excellent  material  from  Waldron,  Crawfordsville,  and  other  celebrated 
localities  of  the  West ;  also  the  Walcott  collection  from  New  York. 

A  full  account  of  the  various  collections  made  use  of  by  us  would 
exceed  the  limits  of  a  preface,  but  we  cannot  refrain  from  making  par- 
ticular mention  of  some  of  them  :  — 

The  collections  in  the  American  Museum  of  Natural  History  at  New 
York,  containing  many  of  the  type  specimens  of  the  New  York  Palaeonto- 
logical  Reports,  have  been  at  all  times  accessible  to  us  through  the  courtesy 
of  Prof.  R.  P.  Whitfield,  who  has  been  prompt  to  send  us  such  specimens  as 
we  needed  for  illustration  or  comparison,  and  to  give  us  any  desired  infor- 
mation obtainable  from  the  extensive  material  under  his  charge. 


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INTRODUCTION. 


6 


During  the  lifetime  of  Prof.  Worthen,  the  eminent  Director  of  tiie 
Illinois  Geological  Survey,  and  afterwards  under  the  administration  of  his 
accomplished  successor,  Dr.  Josua  Lindahl,  we  enjoyed  the  privilege  of 
unrestricted  facilities  in  ihe  use  of  the  type  and  other  specimens  in  the 
State  Museum  of  Natural  History  at  Springfield.  The  private  collection 
of  Worthen,  containing  a  large  number  of  tlie  types  of  the  earlier  species 
described  in  Hall's  Iowa  Reports,  was  packed  up  and  inaccessible  wiiilo  he 
held  the  position  of  State  Geologist ;  but  after  his  death,  when  the  col- 
lection was  acquired  by  the  State  of  Illinois  and  incorporated  in  the  State 
Museum,  we  were  permitted  through  the  courtesy  of  Dr.  Linddil  to 
examine  it,  and  were  given  full  use  of  the  valuable  type  specimens.  As 
a  mark  of  our  personal  esteem,  and  in  justice  to  the  memory  of  this 
pioneer  collector  and  geologist,  we  have  inserted  the  name  of  Worthen  in 
the  notation  of  such  of  his  type  specimens  as  are  now  in  the  State  Collection. 
These  types  are  of  great  value,  as  they  are  the  only  types  of  the  early  Bur- 
lington and  Keokuk  species  still  in  existence,  so  far  as  we  know,  with  the 
exception  of  a  few  in  the  Shumard  collection.  We  have  been  unable  to 
obtain  any  information  as  to  the  types  of  Owen  and  Shumard's  descriptions 
in  the  Report  for  Iowa,  Wisconsin,  and  Minnesota,  in  1852,  —  the  first  Sub- 
carboniferous  Crinoids  described  from  the  West.  A  considerable  pnrc  of  the 
collections  made  during  the  first  Iowa  Geological  Survey  are  said  to  have 
been  destroyed  by  fire,  either  at  Burlington  or  Keokuk,  and  it  is  supposed 
that  a  number  of  type  specimens  were  lost  in  this  way.  McChesney's  types 
were  all  lost  in  the  great  Chicago  fire. 

The  collections  in  the  Canada  Survey  Museum  at  Ottawa,  containing 
the  typos  of  all  of  E.  Billings's  Lower  Silurian  species,  and  the  later  ones  of 
Whiteavcs,  have  been  freely  open  to  us  under  the  authority  of  S5l'  Alfred 
Selwyn,  and  through  the  unremitting  courtesy  of  Prof.  J.  F.  Whiteaves. 

Through  the  attention  of  Dr.  C.  A.  White  and  Prof.  C.  D.  Walcott,  we 
obtained  the  use  of  the  types  of  some  of  Meek's  descriptions  in  the  National 
Museum  at  Washington. 

Prof  S.  H.  Williams  of  Ithaca,  New  York,  had  the  goodness  to  furnish 
us  for  examination  the  types  of  species  described  by  him,  from  the  •CTuseum 
of  Cornell  University,  and  some  of  the  types  from  the  Colonel  Jewett 
collection. 

Through  Prof  A.  H.  Winchell  we  had  the  use  of  the  specimens  in  the 
collection  made  by  Dr.  White,  now  in  the  University  Museum  at  Ann  Arbor, 
containing  the  types  of  a  number  of  well  known  Subcarboniferous  species. 


6 


INXUODUCTION. 


To  Dr.  G.  Ilainbiich  of  St.  Louis  \vc  owe  the  facility  of  examining  the 
type  specimens  in  the  Shunuird  collodion  at  the  Washington  University. 

We  are  under  special  obligations  to  Prof.  Borden,  of  Borden  Institute  at 
New  Providence,  Indiana,  for  the  opportunity  of  e.xninining  the  original 
collection  of  Dr.  Knapp,  of  Louisville,  from  the  now  exhausted  Bear  Grass 
locality  near  Louisville,  containing  some  of  the  types  of  species  described  by 
Lyon,  Shumard,  and  Yandell,  which  now  form  a  part  of  the  Museum  of  the 
Borden  Institute. 

To  Prof.  S.  Calvin  we  are  indebted  for  the  loan  of  fine  specimens  from 
the  Hamilton  of  Iowa  and  New  York,  from  which  we  made  descriptions  of 
several  species. 

Our  thanks  are  also  due  to  Prof.  W.  H.  Barris,  of  Davenport,  la.,  who 
gave  us  the  use  of  his  type  specimens  and  other  valuable  material  from 
the  Hamilton  group  of  Iowa  and  Michigan,  which  were  under  his  charge  in 
the  Museum  of  the  Davenport  Academy  of  Science. 

We  also  avail  ourselves  of  this  opportunity  of  expressing  our  high  appre- 
ciation of  the  favors  extended  to  us  by  Dr.  G.  LindstrUm,  of  the  National 
Museum  of  Sweden  at  Stockholm,  in  which  are  deposited  the  magnificent 
collections  of  Crinoids  from  the  L'pper  Silurian  of  Gotland  that  formed  the 
basis  of  Angolin's  descriptions.  Not  only  has  he  at  all  times  allowed  us  the 
privilege  of  having  special  drawings  made  from  unique  specimens  in 
the  Museum,  but  on  one  occasion,  on  learning  of  the  difliculty  under  which 
we  labored  from  want  of  adequate  material  to  study  the  genus  Crotalocrinus, 
he  sent  us,  without  solicitation,  a  series  of  specimens,  including  some  of 
Angelin's  originals,  with  liberty  to  retain  them  as  long  as  might  be  necessary 
for  the  examination  we  desired  to  make. 

We  have  also  to  acknowledge  our  indebtedness  to  Mr.  Walter  R.  Billings, 
of  Ottawa,  Canada,  for  the  loan  of  types  of  Trenton  species  in  his  own  col- 
lection, and  also  for  his  good  offices  in  securing  for  our  use  the  collections 
of  Messrs.  Stewart  and  I.  F.  Sowter.  Besides  this,  Mr.  Billings  has  from 
time  to  time  furnished  us  valuable  notes  in  relation  to  many  rare  and  inter- 
esting forms,  often  illustrated  by  exquisite  drawings  from  his  own  hand. 
We  extend  our  thanks  to  Mr.  John  Stewart  and  Mr.  I.  F.  Sowte; ,  of  Ottawa, 
Canada,  for  the  use  of  their  specimens,  —  Mr.  Stewart  having  at  one  time 
sent  us  his  whole  collection  for  study. 

To  the  owners  of  private  collections  in  the  United  States  our  obligations 
are  so  numerous  and  varied  that  we  cannot  attempt  to  express  in  proper 
terms  of  appreciation  our  indebtedness  to  each  one. 


ri 


INTRODUCTION. 


It  is  especially  (lifFiciilt  for  us  to  express  our  obligations  to  Mr.  Victor 
VV.  Lyoii,  of  Jcfl'ursoiiviilo,  Iml.,  who  with  the  utmost  liberality  placed  his 
own  collection  at  our  disposal,  and  also  that  of  his  father,  the  late  Major 
Sidney  S.  Lyon,  through  which  wo  secured  tho  use  of  all  the  types  of  tho 
species  described  by  Major  F.yon  himself,  and  by  Lyon  and  Cassodiiy. 

Mr.  Lisbon  A.  Cox,  of  Keokuk,  la.,  gave  us  acciss  to  his  extensive 
and  unique  collection  from  the  Keokuk  limestone,  containing  tho  types  of  a 
largo  number  of  species  described  by  Worthen  in  Vol.  VII.  of  the  Illinois 
Reports. 

Mrs.  Yandell,  of  Louisville,  Kentucky,  has  sent  us  for  examination  some 
rare  types  in  the  collection  of  tho  lato  Dr.  L.  P.  Yandell.  We  tender  our 
special  thanks  to  this  venerable  lady  for  the  efforts  she  made  to  serve  us. 

To  the  natui-alists  and  collectors  of  Cincinnati  and  vicinity  we  are 
indebted  for  great  facilities  in  studying  the  crinoidal  fauna  of  the  Lower 
Silurian  of  that  region.  Mr.  I.  II.  Harris,  of  Waynesville,  Ohio,  placed  at 
our  disposal  the  species  of  his  maguilicent  collection  of  Hudson  River  Cri- 
noids.  Mr.  S.  A.  Miller  favored  us  with  the  loan  of  his  valuable  types  of 
Lower  Silurian  species.  Mr.  E.  0.  Ulrich,  of  Newport,  Ky.,  has  sent  us  for 
examination  the  types  of  his  species,  and  besides  other  instructive  speci- 
mens. He  also  used  his  influence  in  our  behalf  with  Messrs.  Oeh  and 
Vaupel,  who  placed  some  of  tlieir  finest  specimens  in  our  hands. 

Dr.  E.  N.  S.  Ringueberg,  of  Lockport,  N.  Y.,  has  sent  us  the  types  of 
his  species  of  the  Niagara  group  of  Western  New  York,  with  liberty  to  use 
them  as  we  might  find  desirable. 

To  Prof.  J.  M.  Clarke,  of  Albany,  N.  Y.,  we  are  indebted  for  the  use 
of  valuable  type  specimens  from  the  Hamilton  group  of  New  York,  then  in 
his  private  collection,  but  since  passed  into  the  New  York  State  Cabinet. 

Mr.  Thomas  A.  Greene,  of  Milwaukee,  Wis.,  placed  in  our  hands  a 
large  collection  of  natural  casts  from  the  Niagara  group,  including  types  of 
the  Waukegan  species ;  and  Mr.  W.  C.  Egan,  of  Chicago,  a  similar  collection 
from  near  Chicago,  containing  the  types  of  the  species  described  from  that 
locality. 

Mr.  F.  A.  Sampson,  of  Sedalia,  Mo.,  gave  us  the  use  of  his  collection, 
containing  the  types  of  a  large  number  of  species  described  by  S.  A.  Miller 
in  the  Missouri  and  Indiana  Reports ;  and  Prof.  R.  R.  Rowley,  of  Louisiana, 
Mo.,  furnished  us  the  types  of  liis  species. 

We  are  also  indebted  for  the  use  of  specimens  and  friendly  acts  in  vari- 


8  INTRODUCTIOX. 

ous  ways  to  Mr.  Asa  S.  Tiffany,  of  Davenport,  Dr.  C.  C.  Wnshbiirn,  of  Wal- 
(Iron,  Ind.,  Dr.  Mosua  Elrod,  of  IIiirtHvillo,  Inil,  Rov.  II.  Ilerzor,  of  Hercu, 
Ohio,  l{ev.  John  Davis,  of  Ijouisiana,  Mo.,  Mr.  D.  II.  Todd,  of  Kannas  City, 
Mo.,  Mr.  G.  M.  Nickels,  of  Sparta,  111.,  Mr.  E.  Brown,  of  Bi'lfaMt,  N.  Y.,  and 
others. 

To  Dr.  Horace  O.  Griffith,  formerly  of  Burlington,  now  of  Philadclpliin, 
wo  express  our  grateful  acknowledgments  for  his  intelligent  and  unremitting 
efforts  to  aid  us  in  the  pro.secution  of  thiswork,  and  for  his  steadfast  devo- 
tion to  our  interests  manifested  upon  every  occasion. 

We  also  bear  in  kindly  remembrance  our  former  townsman,  Mr.  James 
Love,  whose  fine  collection  was  always  at  our  disposal,  and  which,  together 
with  one  made  by  Mr.  J.  W.  Giles,  afterwards  passed  into  our  hands. 

Dr.  Charles  R.  Keyes  has  at  all  times  exhibited  a  lively  interest  in  the 
progress  of  our  work,  and  we  owe  to  him  not  only  the  procurement  of  some 
valuable  specimens,  but  other  friendly  ofliees. 

Nor  do  we  forget  our  good  friend,  Orestes  St.  John,  whose  keen  eye  and 
rare  juilgment,  and  no  less  his  skilful  pencil,  have  always  been  at  our  ser- 
vice. We  have  from  him  some  unsurpas,sed  structural  drawings,  and  he 
presented  us  several  unique  Crinoids  from  the  Coal  Measures  of  Kansas. 

Our  thanks  are  due  to  Mr.  Wm.  F.  E.  Gurley,  of  Danville,  III,  for  the 
use  of  specimens  from  Waldron,  and  to  Mr.  A.  C.  Benedict,  of  Indianapolis, 
for  the  use  of  specimens  obtained  by  him  at  St.  Paul,  Ind. 

In  addition  to  the  facilities  above  mentioned,  we  have  had  during  the 
preparation  of  this  work  our  own  collection,  which  contains  authentic  speci- 
mens of  nine-tenths  of  the  species  of  Crinoids  described  from  the  United 
States,  and  two-thirds  of  all  the  European  species.  From  many  of  the  typical 
localities  we  have  been  able  to  obtain,  either  by  purchase  of  local  collections, 
or  by  personal  exertions,  largo  series  of  specimens,  by  means  of  which  it  has 
been  possible  to  study  m  many  cases,  and  among  different  genera,  the  indi- 
vidual variation  existing  in  the  limits  of  a  species,  and  the  modifications  due 
to  growth. 

In  looking  over  the  descriptions  it  will  probably  surprise  some  of  the 

authors  to  find  so  many  of  their  species  placed  in  the  synonym  lists,  but 

we  were  obliged  to  do  so  after  careful  study  and  comparison  with  authentic 

specimens. 

CHARLES  WACHSMUTH. 

FRANK  SPRINGER, 
BcRLiNOTON,  Iowa,  May  1,  1894. 


Received  at  Cambridge,  September  1,  1894. 

ALEXANDER  AOASSIZ. 


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TABLE  OF  CONTENTS. 


INTRODUCTOUY   PART. 

Pahe 

Inthodcctiom 1-10 

IIhtuuical 11-31 

TEHMiNOLOor 32-37 


MUIU'IIOLOGICAL  I'AHT. 


Primauy  and  Supplementary  Plates     88 

TiieI'lates  of  the  AiiAtTiNAL  System  38-88 

The  Stem  and  its  Appcndagos      .     38-,'j2 

Dasols  niul  Iiifrabasuls  ....     M-'S 

The  UaiUals 08-73 

The  Arms  and  Piimkn  ....     73-88 
The  Plates  of  the  Actinal  System  88-101 

The  Orals 88-89 

Mouth  and  Ambulacra 90 


The  Supplementary  Plates     .     .     .     l(i.5 
The  distrlbutiou  of  the  Plates  and 
IhcU'  relations    to  the  diirercnt 

groups     105-123 

The  Anal  Plates  and  the  Anna      .  121-1.'!9 
Internal   Cavity  of  the  Calvx    110-112 
Tlie    Clianil)ered    Organ    and     the 

Axial  Canals 140 

Tlie  Convoluted  Organ 113 


SYSTEMATIC  PART. 


Classification 141-172 

Definition  of  the  Cr'noidea  and  their 

Primary  Subdivisions  .     .     .     .  1C9 
Analysis  of  the  Families    ....  170 
Geological  and  Geograi)hical  Distri- 
bution of  the  Camerata    .     .     .  172 
Descriptive. 

Reteocrinidae 173-187 

Analysis  of  tlio  Genera 173 

Geological   and    Geographical    Dis- 
tribution    173 

Reteocrinus 170 

Xenocrinus 182 

Tanaocrinus 185 

Thysanocriniiiae 188-214 

Analysis  of  the  Genera 188 

Geological  and  Geographical  Distri- 
bution         188 

Tliysanocrinus 190 

Ptychocrinus 197 

Hyptiocrinus 200 

Idiocrinus 202 

Lampterocrinus 207 

Siphonocrinua 209 

Rhodocrinidae 215-263 

Analysis  of  the  Genera 215 

Geological  and  Geographical  Distri- 
bution        216 

Rhodocrinus 218 

Gilbcrtsocrinus 233 


Thylacocrinus 248 

Diabolocrinus 249 

Archa->ocrinu8 263 

lihaphanocrinus 258 

Lyriocrinus 201 

Melochinidae 264-329 

Analysis  of  the  Genera       ....  204 
Geological  and  Geographical  Distri- 
bution         265 

Melocriuites 267 

Glyptocrinus 267 

Periglyptocrinus 277 

Stclidiocrinus 279 

Mariacrinus 281 

Macrostylocrinus 285 

Melocrinus 292 

Dolatocrinites 304 

Technocrinus 304 

Allocrinus 306 

Centrocrinus 308 

Dolatocrinus 310 

Stereocrinus 324 

Iladrocrinus 327 

Calvptocrinidae 330-359 

Analysis  of  the  Genera 330 

Geological  and  Geographical  Distri- 
bution        330 

Eucalyptocrinus 332 

CaUicrinus 353 


T  II  E 


CRLVOIDEA    vJAMEUATA    OF    ^'011111    AMERICA. 


INTRODUCTORV    TART. 


I.    lll.STOUICAL. 

The  fifHt  roforonco  to  FohhII  CriiioidH,  nccording  to  Do  Koninck,  'vna 
miulo  by  Aj^ricola  in  tho  second  half  of  tho  Hixtoentli  century.  lie  distin- 
l^uislied  between  Tmc/ii'lcs,  Eiilrochus,  and  Encnnua.  The  former  name  ho 
applied  to  all  detached  Htem-joints ;  Enfroc/tiis  to  a  series  of  joints,  and 
Encnnns  to  tho  calyx  of  Eiicn'mis  liUifnriiih,  at  tlmt  time  the  only  Crinoid 
in  which  a  crown  had  been  found  in  connection  with  tho  stem.  As  early 
as  tho  seventeenth  and  eighteenth  centuries  the  crinoidal  remains  received 
tho  attention  of  a  large  number  of  writers,  some  of  whom  regarded  them  as 
plants,  others  as  animals. 

Rosinus,  who  lived  at  tho  beginning  of  tho  eighteenth  century,  was  the 
first  writer  to  show  that  tho  Crinoidv  were  not  plants,  as  before  then  gene- 
rally supposed,  but  wore  closely  related  to  tho  Asterids,  and  especially  to 
tlie  group  which  afterwards  received  the  name  Euryale.  He  also  supposed 
that  tho  Trochites  and  Entrochites  were  parts  of  Encrinus,  and  not  inde- 
pendent bodies. 

An  important  advance  in  the  knowledge  of  the  Crinoids  was  made  by 
Guettard,*  who  described  the  first  recent  Stalked  Crinoid  that  ever  came  to 
Europe.  lie  gave  this  species,  which  was  afterwards  known  as  Pentacn'niis 
cnpiit-mcdiisce  Lamk.,  the  popular  name  "  Palmier  marin,"  and  took  it  to  be 
the  type  of  all  fossil  Crinoids  with  pentagonal  stem,  as  opposed  to  those 
with  a  round  stem,  of  which  he  thought  the  living  type  had  not  been  dis- 
covered.    He  gave  a  moderately  fair  description  of  its  structure ;  but  added 

•  M^moirc  siir  les  Encrinitcs  et  les  pifcrrcs  dtoili'es,  duns  leqiiel  on  trnitera  aussi  dcs  Entroques.     (Miiiii. 
de  I'Acad.  Roy.  Soo.  do  Paris,  1755  (published  1761),  pp.  224-318. 


12 


THE  CRINOIDEA  CAMERATA  OF  NOBTH  AMERICA. 


I    \ 


/> 


little  as  to  the  systematic  position  of  the  Crinoids  generally,  stating,  how- 
e\    ,  that  they  were  neitiier  Polyps  nor  Starfishes. 

Linnd,  throughout  all  the  editions  of  his  '•Systema  Naturae,"  placed 
the  Crinoids  among  the  corals.  Bluincnbach  *  has  the  credit  of  having  been 
the  first  writer  who  ranked  them  with  the  Asteroids  and  Ophiurids  among  the 
order  "  Vermes  crustacei,"  which  corresponds  approximately  to  our  pres- 
ent Echinoderms.  Lamarck,  in  the  first  edition  of  his  "  Systeme  des  Ani- 
maux  sans  vertobres,"  published  in  1801,  ranged  them  among  the  "Polypes 
a  rayons  coralligenes,"  along  with  Gorgonia,  Umbellula,  and  Pennatula;  but 
he  afterwards  modified  this  opinion,  and  in  1812  t  referred  the  Crinoids  to 
the  '•  Polypes  flottants,"  which  he  arranged  next  to  the  Kadiata.  In  1810  J 
he  placed  the  Encrinites  (Stalked  Crinoids)  among  the  Polyps,  but  the 
Comatulae  (Free-floaters)  among  the  Echinoderms.  Schweigger  §  directed 
attention  to  the  close  resemblance  that  he  found  to  exist  between  the  arm 
structure  of  stalked  Crinoids  and  Comatuloe,  and  he  considered  the  two 
forms  to  be  closely  related.  Cuvier  in  1817,  ||  and  again  in  1830,]f  placed 
the  Crinoids  among  the  Echinoderms. 

The  name  "Crinoidea,"  with  the  rank  of  a  family,  was  proposed  in  1821 
by  J.  S.  Miller,  for  the  lily-shaped,  radiate  animals  which  theretofore  had 
been  known  as  Encrinites  and  Pentacrinites.  He  restricted  the  group  to  the 
Brachiate  forms,  and  to  those  provided  with  a  stem,  as  appears  by  the  follow- 
ing  definition:**  "An  animal  with  a  round,  oval  or  angular  column,  com- 
posed of  numerous  articulating  joints  forming  a  cup-like  body  containing 
the  viscera,  from  whose  upper  rim  proceed  five  articulated  fingers."  This 
description  includes  neither  Blastoids  nor  Cystids,  which  were  placed  by 
Miller's  successors  as  subordinate  groups  imder  the  Crinoids.  It  also  ex- 
cludes the  ComatuloB  and  the  genus  Marsujntcs,  which  have  no  stem,  and 
which  probably  for  this  reason  were  referred  by  him  to  the  "  Stelleridoe." 
Among  the  latter  ho  recognized  four  divisions :  "  Comatula3,  Euryale, 
Ophiura,  and  Asteria,"  and  he  placed  Marstijnics  in  the  same  group  with 
Euryale.     Miller  knew  little  of  the  structure  of  the  Comatuloe,  but  enough 


1S12. 


•  Ilaudbiich  der  Naturgescliiclite,  1780. 

f  Extrait  du  cours  de  ZoiJlogie  du  Museum  d'histoire  nnturelle  sur  les  Animaux  sans  vertcbres,  etc. 
2. 

t  Ilis'oire  naturclle  des  Animaux  sans  Vertcbres,  etc.,  1815-1822. 

§  Ilaiii'b.  der  skeletlospu,  uugosliederton  Tliiere,  Leipzig,  1820,  p.  528. 

II  Le  ni-gv".  animal,  1817  (l''),Vol.  IV.,  p.  12. 

^  Op.  eit.    (Ed.  of  1830.) 

**  A  Natural  History  of  the  Crinoidea,  Bristol,  1821,  p.  7. 


HISTORICAL. 


18 


to  be  struck  by  the  rcseniblarico  tlioy  bear  to  the  crown  of  rcuhvn'nm.  and 
bo  pointed  out  that  the  pentagonal  plate  at  the  base  of  the  subgjubose  body 
of  the  Coniatula)  occupies  the  position  of  the  first  column  joint  of  the 
"  Crinoidea." 

Miller  subdiviLled  the  Crinoidea  into  four  groups:  the  Adticulata,  to 
which  he  referred  the  genera  "  Apiooiuitcs,  Encrinilca  and  Pciihicriiii/cs ;"  the 
Semiautici:lata  with  "  Po/criocrinl/ca;"  the  IxAirricuLATA  wi\\i  "  Cfalhocri- 
nilcs,  Aclbiocriiuti's,  Uhodocrinitcs,  and  Plal/jcrinilcs  ;  "  and  the  Coaduxata  with 
"  Eurjmhwriniles."  His  primary  groups  were  based  upon  the  mode  of  union 
between  the  stem  and  calyx,  and  between  the  latter  and  the  arms;  his 
genera  upon  the  number  and  arrangement  of  the  jilates  in  the  dorsal  cup. 
Considering  tliat  in  1821  only  about  twenty-five  species  of  Stalked  Crinoids, 
recent  and  fo.ssil,  were  known,  and  many  of  them  only  from  fi'agmontary 
ppecimens,  we  cannot  help  admiring  the  genius  of  Miller,  who  brought 
order  out  of  chaos,  and  laid  the  foundation  of  the  present  classification  of 
the  Crinoidea.  Ili.s  genera  have  been  generally  accepted,  and  are  now  rec- 
ognized as  the  types  of  well-marked  families. 

Miller  introduced  an  elaborate  terminology,  but  unfortunately  did  not 
always  apply  his  terms  to  the  same  parts.  In  some  of  his  genera  ho  gave 
the  term  "  pelvis  "  to  the  proximal  ring  of  the  plates  within  the  calyx,  in 
others  to  the  plates  of  the  ring  al)ove.  In  Apiocriiins  and  Aclinocriiuia  he 
called  the  radials  "  first  costals;"  the  succeeding  ones  "second  costals,"  and 
the  first  axillaries  "  scapidas."  In  P/iif//criiiii-s,  however,  and  in  Potcrlocvinvs 
and  C'/iif/ifcriiii's, the  radials  ai'e  his  sc.ipula;,  and  are  followed  by  arm  plates. 
Pla'ijcrinus,  according  to  Miller,  has  no  costals  at  all ;  but  in  the  dicyclic 
Cyathocrinus  and  Pufemciimis  costals  are  said  to  be  represented  by  the  plates 
of  the  interradial  basal  ring. 

A  year  after  the  appearance  of  Miller's  work,  Schlotheim  published  the 
first  part  of  the  Supplement  to  his  Petrofactenkunde,*  reproducing  therein 
Miller's  figures  together  with  his  own,  and  adopting  his  generic  and  specific 
names.  A  year  later,  however,  in  the  second  part  of  that  work,  he  withdrew 
Miller's  generic  names,  and  referred  all  Stalked  Crinoids  back  to  Eiwrinus  and 
Pentacrimts  respectively. 

Goldfuss  in  his  great  woi-kt  adopted  Miller's  classification  and  termi- 
nology.    Cumberland  t  did  not  consider  Miller's  name  "  Crinoidea"  appro- 

*  Naclitraso  ziir  rptiTfactoukunilo,  1^23-193.'?  (2  Biiiulc,  mil  37  Kupfci-Platteuj. 
t  Potrofricta  Gormaniw,  Diisselilnrf,  lS2(i-1833. 
%  Udiquix  couservatoe,  Bristol,  1820. 


i 


i  I 


14 


THE  CRINOIDEA  CAMEKATA  OF  NORTH  AMERICA. 


priate,  as  not  a  single  Encriims  or  Pcntacrimis  resembled  in  the  smallest 
degree  a  lily,  either  in  stem,  root,  flower,  or  bud.  Nor  did  he  think  it 
absolutely  pioved  that  they  were  anunals  instead  of  coraliue  sensitive 
plants. 

In  1825,  Say  *  described  three  new  species  nnder  the  genus  Pciitrcmk-s, 
which  he  made  the  type  of  a  now  family  of  the  Crinoidea,  and  proposed  for 
it  the  name  Blastoidea.  He  also  described  the  genus  Carz/ocniiitcs,  which  he 
took  to  be  intermediate  between  Ci/ulhocnims  and  Adinocriims.  In  the  same 
year  two  additional  species  of  Peiitrcndtes  were  described  by  G.  B.  Sowerby. 

In  the  years  following  up  to  1840,  a  number  of  new  species  of  Crinoids 
were  described  by  Mantell  (1822),  Pander  (1830),  Steininger  (1831,  1837, 
and  1838),  Goldfuss  (1832  and  1838),  Zenker  (1833),  Phillips  (1835-183G), 
F.  A.  Roemer  (1836  and  1839),  Heisinger  (1837),  Sedgwick  and  Murchison 
(1837),  D'Orbigny  (1837),  Miinstor  (1838-1846),  and  others;  but  they  added 
little  to  the  general  knowledge  of  the  Crinoids. 

L.  Agassiz,  in  his  Prodrome  d'une  Monographic  des  Radiaires  ou  Echino- 
dermes,t  referred  the  Crinoids  to  the  "  order  "  Slclleiiilcs,  together  with  the 
"  genera "  Comalula  and  Marsvpilcs,  which,  as  he  stated,  differ  from  the 
Crinoids  only  in  not  having  a  stem. 

J.  V.  Thompson,  in  1836,  discovered  %  that  the  small  species,  which  he 
had  described  in  1827  as  Pentacrimis  ciiropaus,  loses  its  stem  at  a  more 
advanced  stage  of  growth,  and  changes  into  a  free-floating  Comatula. 
Thompson  also  discovered  the  ovaries  along  the  pinnules. 

Other  important  discoveries  in  relation  to  the  anatomy  and  development 
of  recent  Crinoids  were  made  by  Adams,  Ileusinger,  Savigny,  Delle  Chiaje, 
Blainville,  and  Dujardin.  D'Orbigny  in  1839  described  the  remarkable 
recent  genus  IIulopus,^  a  Crinoid  not  attached  by  a  jointed  stem,  but  by  the 
lower  end  of  the  calyx. 

In  1840  appeared  the  classical  work  of  Johannes  Mliller,  "Uebor  den 
Bau  des  Pentacrinus  caput-medusao,"  ||  which  marked  a  new  era  in  the  history 
of  the  Crinoidea,  and  threw  a  flood  of  light  upon  the  whole  group.  Mliller 
in  this  work  discussed  the  relation  between  the  Pentacrinites  and  Comatulas, 
and  pointed  out  the  anatomical  diflferences  in  the  structure  of  Crinoids  and 

•  Joura.  Acad.  Nat.  Sci.  Pl.ila.,  Vol.  IV.,  pp.  292-200. 

t  Meinoircs  dc  li\  Sociule  des  ScieucL's  Niitiiielk-.s  de  Ncufclmlol,  183,5,  Tom.  T,  p.  IfiS. 

J  Alcmoir  on  tlic  Starfish  of  tlio  gonus  Comrifiifn  (Ediuburgli  New  Tliilos.  ,Tourii.,  Vol.  20,  p.  295. 

§  Wicgmaim's  Arcliiv  I'iir  Natnrgcscliiclitp,  I,  p.  185,  Taf.  5,  Fi2;s.  2-7. 

II  Read  before  the  Berlin  Akadeniie  dcr  Wisscuschaftcn,  April  30,  18iO. 


1 


im 


\ 


HISTORICAL. 


15 


Asterids.  He  also  introduced  a  more  rational  terminology  for  the  plates  of 
the  calyx,  which  is  still  used  by  Zoologists  and  Palaaontologists.  He  proposed 
the  name  "  Bamlia"  for  the  pelvis  jilates  of  Miller,  and  ''  Iiiidiulia"  for  Mil- 
ler's scapulaj  and  costals,  including  the  first  axillary.  When  the  rays  are 
free  above  the  first  radial,  the  axillary  supports  the  arms ;  but  when  that 
plate  forms  a  part  of  the  calyx,  it  is  followed  by  the  "  DisticJialla,"  and  these 
by  the  "  P«/iH«;7«."  For  the  supplementary  plates  he  introduced  the  terms 
"  Intcrnulmlui,  Inlcrdhlkhalia  and  Interpubtttria." 

MUller  divided  the  Crinoids  into  three  great  groups:  the  "  Cnnoidm  Arii- 
culata,"  the  "  Cnnoidca  TesseUaia  "  and  the  "  Crinoidca  Custata,"  which  he 
defined,  and  of  which  he  gave  a  list  of  the  principal  genera. 

Of  the  Arikula/a,  to  which  Miiller  referred  Pciitacrimis,  Apiocrinus,  Encrinm, 
and  the  Comatula9,  he  said  that  the  rays  develop  directly  from  the  base  of  the 
calyx,  and  the  lower  ray  plates  are  united  laterally  by  a  skin,  which  is  either 
naked  or  paved  with  irregular  plates ;  that  this  skin  is  continued  to  the  ven- 
tral disk,  closing  the  ventral  side  of  calyx  and  arms ;  and  that  the  radials 
consist  of  three  successive  plates,  of  which  the  first  and  second,  and  the 
axillary  and  the  first  arm-joint,  are  united  by  muscles. 

MUller's  Tessellata  combine  Miller's  "  Scmiarticulata,"  and  "  Inarticu- 
lata,"  and  include  the  Blastoidea,  Cystidoa  and  the  Cretaceous  genus  Mur- 
supitcs.  The  calyx  is  composed  of  3,  4  or  5  basals,  which  are  sometimes 
separated  from  the  radials  by  a  ring  of  "  parabasals."  Between  the  radials 
there  may  be  •'  interradials,"  and  between  the  distichals  and  palmars,  "  in- 
terdistichals,"  and  "  interpalmars."  The  "Scheitel"  (ventral  disk)  covers 
the  whole  ventral  surface ;  it  is  constructed  of  solid  plates,  united  at  their 
edges. 

The  Tessellata  were  subdivided  by  Miiller  into  two  groups  :  Crinoidea 
tvith  arms,  and  Crinoidea  ivifhoid  arms.  To  the  former  he  referred  all  true 
Crinoids  and  the  Cystid  genus  Cari/omnns,  forms  having  no  separate  anal 
opening  and  no  "  Tentakelfurchen  "  (food  grooves)  upon  the  disk,  and  none 
probably  upon  the  arms.  The  armless  Crinoids  comprise  the  "  Pentremites" 
(Blastoidea)  and  "  Sphaeronites "  (Cystidea),  forms  with  separate  mouth 
and  anus. 

MUller's  classification,  although  a  great  advance  upon  that  of  Miller,  was 
not  accepted  by  the  French  and  English  writers  succeeding  him ;  but  it  was 
revived  later  on  by  Ferd.  Roemer  and  von  Zittel. 

In  1842  a  classification  was  proposed  by  Thos.  Austin  and  Thos.  Austin 


r 


0'  5 


IC 


THE   CUIXOIDEA  CAMEKATA  OF  NORTH  AMERICA. 


II.  LinEUIA  (Free-floaters). 
Uiiathoerinoulea. 
Astnicriiioiilca. 
Comastella. 


Jr.,*  who  uuule  the  Crinoidoa  in  the  widest  sense  a  cliiss  of  the  Echinodor- 
niata,  to  whicli  they  gave  the  name  "  Pinnastella."  Among  the  hitter  they 
placed  as  orders  :  — 

I.  ClOXA  ClSKTl  (Stalked  Criuoids). 
Families :  Apiooriiioidea, 

rutoriocrinoidea. 

Encrinoidea. 

rentaorinoidca. 

IFarsupiocrinoidea. 

I'latyciinoidea. 

Actiiiocrinoidea. 

Dimerocrinoidea. 

Only  the  Platycrinoidea  and  Poteriocrinoidoa  t  were  defined. 

To  the  former  they  referred  the  genera ;  riahjcriims,  Dic/wcrinns,  IJcxa- 
criiiiis,  Cai-yocnims,  and  Cijuthocmms  ;  to  the  latter :  Fo/criocnim,  Si/mhutho- 
criniis,  Kiiracn'mis,  and  Fciitacrmis.  Their  Encrinoidea  include  :  Encrinitcs, 
Eucul/jptocmilcs,-  Cupnsmcrinitcs,  and  Fiir//ocrm/cs ;  their  Marsupiocrinoidea : 
Mursupiooimtes  and  Crotalocrinilrs ;  the  Actinocrinoidea  :  Actinocrinitcs,  Bho- 
doenniks,  Mchcrinilcs  and  TdracriniUs.  The  Austins  placed  the  Blastoidea 
with  the  Sphaeroidocrinoidea,  and  the  reriechinidic  under  the  Cohnnnida. 

D'Orbigny  in  1852$  undertook  to  subdivide  the  Crinoids  (including 
Blastoids  and  Cystids)  into  twelve  families,  which  contain  most  heterogene- 
ous elements.  For  description  he  divided  the  plates  of  the  calyx  into 
zones,  without  reference  to  their  radial  or  interradial  position. 

The  next  classification  Avas  that  of  Ferd.  Rocmer,  who  wrote  in  1855,  § 
and  divided  the  Crinoidea  into  three  great  groups:  — 

I.  ActiiwUlra,  or  true  Ciiiioids,  having  large,  pinnule-bearing  arms. 

II.  Cyst  idea,  Crinoids  in  which  the  arms  are  feebly  developed  or  wanting,  and  mouth 
and  anus  are  separate. 

III.  lllanfoidca,  Orinoids  without  arms,  the  soft  parts  of  the  animal  enclosed  within  a 
calyx,  wUicli  is  closed  from  all  sides,  leaving  only  a  few  openings. 

The  Actinoidea  embrace  : 
A.   Tlie  Astylida,  Actinoidea,  Crinoids  without  jointed  column. 

a.  Attached  hij  thn  lower  face  of  the  calyx. 

Holopocrinidje  and  Cyathidiocrinidse. 

b.  Calyx  free. 

Astylocrinidoe,  Marsupitidte,  Saccocomids,  and  Comatulicla3. 

•  Ann.  and  JLig.  NnN  Hist.,  first  scries,  Vol.  X.,  iip.  103  to  109. 

t  Recent  anil  Fossil  Crinoid's.    Tlios.  Austin  and  Tlioniiis  Austin,  Jr  ,  London,  1S13. 

J  Conrs  elcincnt.airc  do  Paleontologic,  II. 

j  Lctbaca  gcoguoslica  (Ausgabc  HI.),  1535,  pp.  210-285. 


1^ 


j*»,fc;  .i   ii^mim  • 


HISTORICAL. 


17 


B.  Styliila,  Crinoids  with  a  jointed  column. 

a.  The  tegmeii  formed  of  a  shin. 

PentacriuidoB,  Apiocrinidoe,  Eugeniacrinidte,  Encrinidse,  CupressocrinidtB,  Cya- 
thocrinidte. 

b.  The  ventral  surface  covered  by  heavy  plates,  immovably  united. 

PoteriocrinidiB,    Itliodocriuidte,    I'latycriuidaj,    Actiuoci'iuidoe,    Melocriuidte, 
Ctenocrinida?,  Sagenocrinidoe,  Antbocrinidie. 
C.  The  arms  imperfectly  developed. 
Haplocriuidre  and  Gastrocomida'. 

Roomer's  families  are  natural  groups,  except  his  Cyathocrinidae,  among 
which  he  united  a  number  of  widely  different  forms.  But  this  is  partly  due 
to  Miller,  who  had  included  with  Ci/uthocrinns  forms  which  were  afterwards 
referred  even  to  different  orders.  Eoemer,  believing  that  Miller's  typical 
species,  Ci/athocrimts  planus  was  a  Poteriocrinus,  made  his  second  species 
Ci/athociinus  tuherciilatiis,  which  Phillips  in  1843  had  made  the  type  of 
Tcuocrinus,  the  type  of  Ctjathocrhms. 

Together  with  the  Classification  was  published  Roemer's  classical  memoir 
on  the  Cystidea  and  Blastoidea,  of  which  especially  that  of  the  latter  fur- 
nished most  valuable  additions  to  our  knowledge  of  the  morphology  of  that 
group. 

In  1845  appeared  the  Memoir  of  Leopold  von  Buch  on  the  Cystidea.  He 
gives  excellent  descriptions  of  several  genera,  and  places  the  group  at  equal 
rank  with  the  Blastoidea  and  Crinoidea. 

De  Koninck  and  Le  Hon,  in  1853,*  described  a  number  of  new  species 
from  the  mountain  limestone  of  Belgium,  and  proposed  certain  changes  in 
the  terminology  of  the  calyx  plates.  The  proximal  ring  of  plates  he  calls 
"  basals,"  whether  the  species  is  monocyclic  or  dicyclic ;  those  of  the  second 
ring  in  dicyclic  forms  "  sous-radiales."  The  radials  comprise  all  plates  up  to 
the  first  axillary;  and  the  succeeding  plates  of  the  rays,  when  parts  of  the 
calyx,  arc  "  articles  brachiaux,"  otherwise  arm  plates.  The  term  "  inter- 
radialos  "  is  applied  only  to  the  pistes  of  the  four  regular  sides ;  those  of 
the  posterior  side  are  "  pieces  anales." 

Another  classification  was  brought  out  by  Pictet,  in  1857,t  who  divided 
the  Crinoids  into  nine  families.  The  first  and  ninth  of  his  families  contain 
almost  exclusively  Neozoic  forms.  The  former  embraces  the  Comaiitlce  and 
MarsupUes,  to  which  was  added  the  Pala8ozoic  Asf^locriniis  {Agasskocrimis) ; 

*  Rcclierclies  sur  Ics  Crinoides  du  Terrain  Carbonifere  de  la  Bclgique. 

+  Traite  de  Puleoutologie,  par  F.  J.  Pictet,  Paris,  1837,  Tom.  V.,  pp.  278-345. 


IS 


I:? 


18 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


m 


'.]' 


the  latter  fiunily,  to  wliicli  lie  applied  the  name  "  Pycnocrliiitloes,"  is  divided 
into  four  Tribus,  —  the  "  Eiigeniacrinions,  Encriniens,  Apiocriniens,  and  Pen- 
tacriniens."  His  second  and  third  families  comprise  '•  Blastoides  "  and  "  C)s- 
tidees  ;  "  the  remaining  ones,  the  •' Tessellata"  of  Miiller. 

It  is  somewhat  curious  that  Pictet,  while  placing  Cupressocrinus,  Euca- 
li/piocrinus,  and  Crutulocrinus  each  in  a  separate  family,  referred  all  the 
other  Palajozoic  CrinoiJs  to  only  two  families,  —  the  "  Ilaplocrinides"  and 
"  Cyathocrinidcs."  Ilis  Ilaplocrinides  embrace  Ilaplocrinus,  Coccocriiius,  Cera- 
mocrinus,  Mi/rtilocnnus,  Epudocriitus,  and  Gaslcrocoma ;  all  the  other  Palasocri- 
noidea  were  placed  under  the  Cyathocrinidcs.  It  is  difficult  to  understand 
upon  what  ground  Pictet's  families  were  based.  His  "  Polycrinides,"  with 
Eucaljptocriims,  have  closer  affinities  with  Mclomims  and  Dolatocnints  than 
these  with  Cz/athocriiuts ;  while  Cupressocrinus  agrees  closer  with  the  Haplo- 
crinides  than  many  of  the  Cyathocrinidcs  among  themselves. 

Pictet  subdivided  the  Cyathocrinitns  into  four  tribus,  —  the  "  Cj'atho- 
criniens,"  the  "  Actinocriniens,"  the  "  Carpocriniens,"  and  the  "  Phitycri- 
niens,"  —  of  which  the  first  are  dicyclic,  the  last  monocyclic;  while  the 
Actinocriniens  and  Carpocriniens  are  in  part  monocyclic  and  in  part  dicyclic. 
He  did  not  discriminate  between  genera  in  which  the  lower  brachials  form 
part  of  the  calyx  and  tho.ee  in  which  they  are  free,  nor  did  he  pay  the  least 
attention  to  the  presence  or  absence  of  anal  plates. 

The  classification  of  Pictet,  although  not  so  satisfactory  as  that  of  Roemer, 
was  accepted  by  Dujardin  .and  Hupe.*  The  latter,  however,  changed  the 
sequence  of  the  families,  making  the  "Cystidees"  the  first  family,  and 
placing  the  "  Comatulides  "  last. 

In  America,  up  to  1858,  little  attention  had  been  paid  to  the  study  of 
Crinoids.  Of  the  fourteen  hundred  American  species  that  are  now  described, 
oidy  about  .seventy  were  then  defined.  In  1843  and  1851,  Iliill  had  de- 
scribed a  moderate  number  from  the  Silurian  in  the  P.iloDontology  of  New 
York,  Vols.  I.  and  II.,  and  a  few  additional  ones  through  the  Regent's 
Reports  at  Albany.  Owen  ami  Shumard,  in  1852,  United  States  Geological 
Report  of  Wisconsin,  Iowa,  and  Minnesota,  described  nineteen  species  from 
the  Subcarboniferous  of  the  Mis,sissippi  Valley,  mostly  from  the  Burlington 
group;  and  Shumard,  in  Swallow's  Missouri  Geological  Report  of  1855, 
twelve  species  from  the  same  horizon.  Tiie  few  remaining  species  had  been 
described  by  Conrad,  Roemer,  Casseday,  and  Yandell  and  Shumard. 

•  Histoire  Naturelle  dcs  Zoophytes  Ecbiuodermes,  i)ar  M.  F.  Dujardiu  et  M.  U.  Hupe,  Paris,  1862. 


HISTORICAL. 


10 


About  the  year  1858  the  interest  of  the  American  Palneoutologists  wa.s 
aroused  by  remarkable  discoveries  of  Crinoids  in  the  Southern  and  Western 
States.  Troost,  at  the  meeting  of  the  American  Association  for  the  Advance- 
ment of  Science,  in  1850,  reported  the  ac()uisition  of  eighty-si.\  new  species, 
with  sixteen  new  genera,  from  the  State  of  Tennessee.*  This  discovery,  liow- 
ever,  was  totally  eclipsed  by  the  wonderful  finds  in  the  Northwest,  where,  at 
Burlington  alone,  upwards  of  three  hundred  species  were  obtained,  which  for 
beauty  and  excellence  of  preservation  surpassed  anything  that  had  ever  been 
seen  before.  This  one  locality  furnished  a  greater  number  of  species  than 
had  been  described  from  America  and  Europe  together  up  to  1857  ;  and 
while  before,  with  a  few  exceptions,  only  calices  had  been  ol)tained,  now 
hundreds  of  specimens  were  found  in  wliich  arms,  stem,  and  occasionally 
the  root,  were  preserved.  The  collections  which  were  made  at  that  time 
by  Wachsmuth,  Barris,  Dr.  Thieme,  and  Hon.  B.  J.  Hall,  of  Burlington, 
and  which  were  afterwards  secured  by  Prof.  L.  Agassiz  for  the  Museum  of 
Comparative  Zoology,  give  testimony  to  the  energy  and  enthusiasm  with 
which  collecting  was  carried  on  in  those  days.  The  same  interest,  often 
mingled  with  jealousy,  was  manifested  by  the  men  of  science,  who,  anxious 
to  publish  the  new  forms,  and  fearing  they  might  be  preceded  by  competi- 
tors, brought  out  preliminary  descriptions  to  secure  priority  for  their  species. 
These  descriptions,  in  many  cases,  were  so  indefinite  that  the  identification 
of  the  species  was  almost  impossible,  and  this  created  considerable  annoyance 
and  labor  to  later  writers. 

About  the  same  time  other  large  deposits  of  Crinoids  were  discovered  in 
Indiana.  Crawfordsville  fin-nished  upwards  of  thirty  species,  Waldron  and 
Hartsville  nearly  twenty.  At  the  latter  places  large  collections  were  made 
by  Dr.  Moses  N.  Elrod  and  Dr.  C.  C.  Washburn.  At  Louisville  and  sur- 
rounding country  a  large  number  of  new  species  were  found  by  Lyon, 
Yandell,  and  Dr.  Knapp ;  at  Keokuk,  Iowa,  by  Dr.  Kellogg,  who  afterwards 
discovered  also  the  rich  Crinoid  bed  at  Richfield,  Ohio.  Still  more  success- 
ful as  a  collector  in  the  Keokuk  rock  was  L.  A.  Cox,  who  found  two  local 
deposits  of  finely  preserved  Crinoids,  —  one  at  Keokuk,  the  other  at  the 
opposite  side  of  the  river,  which  produced  nearly  forty  new  species.  Dr. 
Roeminger  discovered  the  Crinoid  bed  in  the  Hamilton  group  at  Alpena, 
Michigan ;  Springer  that  of  Lake  Valley,  New  Mexico,  in  the  Burlington 

*  These  genera  niul  species  were  described  by  Troost  in  a  monograph.  Tlie  manuscript  was  deposited 
at  the  time  of  his  death  in  the  Smithsonian  Institute,  but  was  never  pul)lislicd,  and  ho  did  not  receive  the 
credit  which  is  probably  due  to  him. 


20 


THE  CRINOIDEA  CAMERATA  OP  NORTH  AMERICA. 


ii 


i| 


group.  Among  tlic  pioneer  collectors  must  bo  mentioned  also  Mr.  Anthony, 
U.  P.  James,  and  C.  B.  Dyer,  of  Cincinnati ;  I.  II.  Harris,  of  Waynesville ; 
J.  Kelly  O'Neall,  of  Lebanon,  Ohio;  Thomas  A.  Greene,  of  Milwaukee; 
W.  C.  Egan,  of  Chicago,  —  who  all  made  large  local  collections  which  have 
furnished  many  type  specimens. 

Within  the  last  ten  years  three  most  remarkable  finds  were  made  in  the 
West :  —  the  first  at  Le  Grand,  near  Marshalltown,  Iowa,  in  the  Kinderhook 
group ;  the  second  on  Indian  Creek,  ten  miles  from  Crawfordsville,  Indiana, 
in  the  Keokuk  group ;  and  the  other  in  the  Upper  Coal-measures  at  Kansas 
City.  The  Le  Grand  bed  furnished  about  twenty-three  new  species,  not 
counting  the  Blastoids.  Of  the  latter,  two  species  of  Orophocriiiiis  are  repre- 
sented, and  in  quite  a  number  of  their  specimens  the  stem  and  pinnules  are 
preserved.  Most  of  the  Crinoids  have  arms  and  stems,  and  some  of  them 
roots.  The  crinoidal  layer,  which  is  but  an  inch  or  two  thick,  furnished 
many  excellent  slabs.  We  have  one  in  our  cabinet  about  a  yard  in  diam- 
eter, on  which  ninety-five  specimens  are  exposed,  both  sides  of  it  being 
thickly  studded. 

Tiie  Indian  Creek  locality  was  discovered  by  the  late  Charles  S.  Beachler 
while  collecting  for  us.  It  proved  to  be  a  local  deposit  in  the  bed  of  tlie 
creek,  not  over  twenty  feet  in  diameter,  and  covered  over  a  foot  deep  by 
water.  Too  much  credit  cannot  be  given  to  Mr.  Beachler,  who  obtained 
under  the  most  trying  circumstances  several  thousand  specimens,  repre- 
sented by  nearly  forty  species.  The  specimens  in  places  were  so  plentiful 
that  more  than  half  of  tliem  had  to  be  sacrificed  to  save  the  others.  The 
preservation  is  excellent,  and  in  some  respects  surpasses  that  of  any  other 
locality. 

The  bed  at  Kansas  City  is  in  the  heart  of  the  city.  It  was  di.scovered  by 
Sidney  J.  Hare  in  the  excavation  for  a  large  building.  Only  seven  species  of 
Crinoids  were  found,  but  they  are  of  exquisite  beauty,  and  being  embedded 
in  a  soft  clay,  are  of  most  excellent  preservation.  Good  collections  were 
made  here  by  David  H.  Todd,  Sidney  J.  Hare,  S.  A.  Howe,  and  E.  Butts. 

Almost  as  fast  as  new  discoveries  were  made  the  species  were  described, 
and  in  1865  the  number  of  American  Crinoids  had  increased  to  six  hundred 
species.  In  1858  appeared  the  Iowa  Report,  Vol.  I.,  by  James  Hall,  in 
which  he  described  over  ninety  species  of  Crinoids,  not  counting  the  Blas- 
toids, and  in  the  following  year,  in  a  Supplement  to  that  Report,  .seventy- 
four  additional  ones.     In  1861  Hall  issued  a  paper  entitled  "  Description  of 


i 


..--m-tgi"^^-^ 


:^w>~«vwcw» iaimwr»iar.uwg^--  ; ■  '•i/mm'-^K .«'«P'  • 


HISTORICAL. 


21 


I 


New  Species  of  Crinoklea,  Albany,  18G1,"  in  which  ho  gnve  on  eighteen 
pages  preliminary  notices  of  one  hundred  and  eleven  Hpeeies.  A  large  num- 
ber of  these  descriptions  remain  in  that  shape  to  this  day,  while  some  of  the 
species  were  redescribed  by  him  in  the  Boston  Journal  of  Natural  History, 
Vol.  VII.  In  the  Puhuontology  of  New  -k,  Vol.  III.,  Hall  described 
twenty-six  species  from  the  Ilelderberg  groups,  —  some  of  them,  however, 
from  arm  or  stem  fragments,  —  and  from  eighty  to  ninety  additional  ones 
through  the  dill'ereut  Annual  Reports  of  the  N\'w  York  State  Museum. 

A  largo  number  of  species  were  described  by  Meek  and  AVorthen, 
and  after  Meek's  death  by  Worthen  ;  they  amount  to  two  hundred  and 
seventy  species,  with  ten  new  genera,  all  well  illustrated.  Another  lot  was 
descrilied  by  Lyon  and  Casseda\',  and  by  Lyon  individually ;  in  all  thirty-one 
species,  with  six  now  genera.  Dr.  C.  A.  White  described  thirty-five  species, 
and  made  three  new  genera.  In  Canada,  E.  Billings  described  some  forty 
species  from  the  Trenton  and  Hudson  River  groups,  with  seven  new  genera. 
In  later  years  the  most  prolific  species-maker  was  S.  A.  Miller,  who  increased 
the  number  of  species  quite  considerably.  Many  of  his  species  have  proved 
to  be  synonyms,  and  while  some  of  his  new  genera  will  be  accepted  by 
every  writer,  others  will  go  into  oblivion.  Additional  species  were  described 
by  Whitfield,  Wetherby,  Ulrich,  Barris,  S.  II.  Williams,  Wiiiteaves,  Ringue- 
berg,  Wachsmuth  and  Springer,  Walter  R.  Billings,  Keyes,  Rowley  and 
Hare,  and  others. 

The  American  Palasontologists  followed  the  termuiology  of  De  Koniuck, 
aid  their  descriptions,  as  a  rule,  are  concise  and  readily  understood.  But 
few  writers  besides  ourselves  discussed  morphological  questions,  and  S.  A. 
Miller,  Prof  Chapman,  and  we,  are  the  only  ones  who  attempted  to  classify 
the  Crinoids. 

Billings,  like  most  of  the  earlier  writers,  believed  that  the  opening  in  the 
disk  of  Palaeozoic  Crinoids  represented  mouth  find  anus  combined.*  He 
pointed  out  that  the  grooves  and  galleries,  passing  out  from  the  centre  of 
the  disk  at  the  inner  floor,  are  connected  with  the  ambulacral  system,  and 
communicate  through  the  arm  openings  with  the  arm  grooves,  but  do  not 
enter  the  tegminal  aperture,  which  he  found  to  be  interambulaeral.  When 
Billings  took  iip  this  question  again  in  1869,t  presuming  that  the  aperture 
represented  the  mouth,  he  concluded  that  in  the  earlier  Crinoids,  in  Blas- 

•  Geol.  Surv.  of  Canada;  Decade  IV.  pp.  14  to  17. 

t  Notes  on  the  Structure  of  the  Crinoidea,  Cystidea  and  Blastoidea  (Amer.  Journ.  of  Sci.  and  Arts  (2d 
series),  July,  ISfig,  and  January  and  September,  1870. 


V  ; 


22 


THE  CRINOIDEA  t'AMEUATA  OF  NORTH  AMERICA. 


tuidd  luul  iimny  C^'Mtuld,  the  iiiuuth  wns  di^tconiiuetcd  from  tlie  niiibulacra; 
and  that  in  those  Cystidn  hi  wliicli  inoro  than  one  opening  is  represented, 
the  lateral  one  is  the  mouth,  and  not  tlie  central  one,  as  had  been  generally 
supposed. 

A  difl'erent  interpretation  of  the  opening  was  given  l»y  Schultzo,  Sir 
Wyville  Thomson,  Dr.  W.  B.  Carpenter,  Dr.  Lilti<en,  Loven  and  Waclis- 
muth,  who  maintained  that  the  month  of  all  Echinoderms  was  located  in 
the  centre  of  radiation,  and  insisted  that  the  intcrambulacral  opening  was 
the  anil-'.  SehuUze  *  could  not  understand  how  a  Crinoid  with  an  interam- 
bulaond  mouth  could  be  sufTiciently  provided  with  food,  even  if  the  arms 
were  prciiensiie  organs,  v/hieh  they  were  not.  lie  .stated  that  Billings's  im- 
portant discovery,  that  the  ambulacra  enter  the  mouth  by  the  arm  ojienings, 
left  but  little  doubt  that  the  mouth  of  the  older  Crinoids  was  subtogminnl 
and  central ;  that  the  food  entered  the  body  through  the  arm  openings,  and 
was  carried  underneath  the  tegmen  to  a  common  oral  centre.  His  views 
were  corroborated  by  Meek,t  who  saw  Wachsmuth's  famous  specimen  (PI. 
v.,  fig.  10),  and  found  the  nnibulacral  tubes  intact  beneath  the  tegmen. 
These  observations  were  confirmed  by  Wachsmuth,|  who  had  discovered 
additional  specimens  with  the  ambulacra  preserved,  and  most  instructive 
natural  casts,  in  which  the  course  of  the  ambulacra  is  indicated  by  ridges 
upon  the  surface. 

In  England,  for  a  long  time,  very  little  attention  was  paid  to  the  study 
of  fossil  Crinoids,  and  many  well  known  forms  are  undescribed  to  this  day. 
Among  the  earlier  English  writers  were  Mantell,  Cumberland,  Parkinson, 
Phillips,  McCoy,  Sedgwick,  and  the  Austins.  Their  descriptions  in  many 
cases  are  so  primitive  that  neither  genera  nor  species  can  be  identified. 
They  were  followed  by  the  writings  of  Rofe  and  Grenfell,  and  these  ul 
Dr.  P.  II.  Carpenter  and  F.  A.  Bather,  whose  excellent  work  attracted  the 
attention  of  every  earnest  student  of  Crinoid.s,  and  opened  a  new  era  in  the 
history  of  paloeontological  research.  In  France  but  little  work  was  done 
upon  Pahvozoic  Crinoids.  Oehlert  described  a  number  of  interesting  De- 
vonian forms,  and  among  them  several  new  genera.  De  Loriol,  so  well 
known  for  his  Monographs  on  the  Crinoids  of  Switzerland  and  France, 
directed  his  attention  exclusively  to  Neozoic  forms. 

•  Monogr.  Ecliinod.  Bill.  Knlk.,  Wien,  1867,  p.  7. 

f  Notes  on  some  points  in  the  Striieture  and  Habits  of  the  Palteozoic  Crinoidoa,  by  F.  B.  Meek  and 
A.  H.  Wortlien  (Proe.  Aead.  Nat.  Sci.  Pliila.,  1869,  p.  323). 
i  Amer.  Journ.  Sci.  and  Arts,  Vol.  XIV.,  August,  1877. 


H 


HI8T01,        L 


28 


In  Gonimny  tlio  priiicipiil  wiitcif*  oi  fowi'i  Crin"' L^  were:  GolilfiiHN, 
MUllcr,  tlio  two  KoeineiH,  Miiiistcr,  Sti'in  gor,  Siinfll)t  -cr.  Qiioii'lt'ilt,  Boy- 
rich,  Scliiiltzo,  V.  Moyor,  v.  Zittel,  FoIImari,  Walthf^i  Kutilsol  Wiij(«)t>r, 
Steininaiin,  Ncuiiiiiyr,  and  Jaukt-I.  Tlic  Belgian  Crinoidx  w«re  inscribed 
hy  do  Koniiick,  and  hy  Fraijiont ;  tlioso  of  Iliissia  by  Kicliwal  'Mcwingk, 
Volbortli,  F.  Sobinidt,  and  TnuitMcbold  ;  a  few  Indian  HpoeiinciiM  i.^.  Wangt-iv 
and  those  from  Australia  by  Ethoridgo,  Jr.,  and  McCoy. 

In  tlio  year  1879  appeared  the  first  volume  of  von  Zittcl's  IIandi)uch  der 
Palicontologie,  with  a  chapter  on  the  Crinoids.  IIo  made  the  latter  a  class 
of  the  Ecliinodorinata,  with  tiiroo  orders :  the  Eneriinilihtt  or  Crinoidca 
scmn  sirido,  the  Blastoidea  and  Cystidoa.  Tiio  Eucrinoidoa  wore  divided 
into  three  sidjorders  :  TesselUda,  Articiilula,  and  Coslntu,  in  which  ho  followed 
Miillor.  Ilia  Tessellata  wore  separated  by  him  into  twonty-six  families, 
which  comprise  all  the  PuliKozoic  forms,  and  the  Cretaceous  genera  Mursiijii/i's 
and  Uiiifucriiiiis  ;  the  Articulata  into  seven  families,  all  Mosozoic  and  recent 
forms  ;  the  Costata  comprise  only  the  Jurassic  Sitcrocinmt. 

The  Tesscllnla  were  defined  by  him  as  having  thin,  immovable  calyx 
plates,  united  by  suture  with  smooth  faces;  "  intorradials"  rigid;  mouth 
subtogminal  and  anus  excentric.  Among  the  families  he  discriminates 
between  forms  in  which  the  tegmon  consists :  — 

A.  Exclusively  of  five  large  orals,  or  in  addition  to  them  small  covering 
pieces  closing  mouth  and  food  grooves.  The  orals  forming  a  pyramid  or  a 
so-called  Consolidalions-AjijjaraL"  Arms  simple  :  Ilaphicrinidw,  risocvinuhe,  and 
CiipressncfhudfP. 

B.  Togmcn  composed  of  small  plates  ;  the  mouth  closed  by  five  orals, 
which  either  are  teguiinal,  or  placed  underneath  the  tegmen  ;  tlio  anus 
excentric.  Dorsal  cup  formed  of  three  (rarely  two)  zones  ;  the  base  gen- 
erally dicyclic.  Arms  strongly  developed  ;  tlieir  ambulacra  covered  by  two 
or  throe  pieces  :  Ilybocrinida;  Cijuihocrimdw,  Taxocriiiidce,  Ichthi/ocriiiidce,  Cro- 
talncnnidce  and  C/ieirocriin'da: 

C.  Tegmen  vcntricose  or  balloon-shapod,  composed  of  numerous  thin 
pieces ;  mouth  subtegminal.  Anal  tube  long  and  heavy,  the  anal  opening 
near  the  base.  Arms  strongly  developed  and  pinnule-bearing :  Hcicrocrmda', 
PoteriooimdcB  and  MnrsvpUida: 

D.  Tegmen  composed  of  heavy,  frequently  nodose  plates ;  the  middle 
portion  covered  by  seven  larger  pieces.  Mouth  subtegminal,  communicating 
with  the  arms  through  plated  tubes.    Anus  often  extended  into  a  long  pro- 


84 


THE  CRINOIDEA  CAMEHATA  OP  NORTH  AMERICA. 


boHcis  witli  tlie  opening  at  tlio  upper  ciul  :  Onxtirocomiiliv,  PlKti/rriiiiifir, 
Cai'i»)criiiiilu',  liriarociiiitilie,  Diim.  irrinitliv,  liuiruiuliocriiiidw,  Aclinocriiiiihf, 
i</i/i(liorriiiiiltf,  Milocrinidiv,  J't>/i/j>il/ulii;  UintucriniJa,  (Jtifiitociinidic  nnil  liho' 
diicriuiilit. 

K.  Teginen  bottlc-Mlinputl,  nnnowcr  ftt  tlio  top  ;  composed  of  Inrgo, 
polygotml  pliites,  regularly  nrraiiged.  ArniH  not  exteniKd  beyond  tlio  cidyx, 
biML-riul ;  placed  between  rib-like  projectiouH,  or  occupying  closed  conipurt- 
ments  :   Cii////>fi>crini(l(t, 

Till'  Arllciihlii  were  defined  by  Zittel  ns  follows :  Plates  of  the  dorsal  cup 
generally  very  heavy,  the  articular  faces  excavated  or  smooth.  Base  mono- 
cyclic, and  Ibrmed  of  five  pieces  ;  exceptionally  dicyclic.  Tognien,  as  a 
rule,  composed  of  a  sUin-Iiko  pcrii-oine,  rarely  plated  ;  mouth  and  food 
grooves  exposed.  The  mouth  central;  nnus  excentricj  orals  present  or 
absent.  Plates  of  the  dorsal  cup  perforated  by  axial  canals,  passing  out 
from  the  dorsal  organ,  ajid  continued  along  the  solid  parts  of  the  arni»  to 
the  ends  of  the  pinnules. 

To  the  Artioilnlii  ho  refers  the  following  families  :  the  Encrinhlce,  Eiii/nm- 
criiiiilif,  IJii/i>/>ii/iP,  Plk'dtdcriinihc,  A/iincriiinlii',  Ptulacrinida'  and  CnDialiilldtf, 

Examining  tho  characters  upon  which  Zittel  separated  tl.o  Tessellata 
from  the  Articulata,  it  appears  that  not  one  of  his  distinctions  holds  good 
throughout  the  families  of  either  group.  The  " Taxocrinidn) "  and  "  Ichth^o- 
criniilif,"  which  he  refers  to  the  Tessellata,  have  a  more  flexible  disk  than 
•either  tho  Encrinidas  or  Apiocrinida),  and  even  than  many  of  the  Penta- 
crinidiv  ;  and,  besides,  have  an  open  mouth  and  open  food  grooves.  Tho 
Poteriocrinid:u  have  a  flexible  disk,  and  well  defined  muscular  articulations 
between  the  radials  and  costals.  Tho  interbrachials  of  Giictlardhrinus  and 
Apiomniis  roissj/aniis  are  as  heavy  and  rigid  ns  those  of  any  Acfiiiocriiiiis,  and 
tho  plates  of  the  dorsal  cup  in  Eiipnchi/crhius  and  Erlsocrmts  are  perforated 
by  axiul  canals,  a  character  which  was  supposed  to  occur  only  among  the 
Articulata.  Neither  is  it  true  that  the  Articulata  are  "rarely  dicyclic"; 
the  reverse  would  be  more  nearly  correct,  for  most  of  them  had  small  infra- 
basnls  in  early  life,  which  gradually  fused  with  the  stem.  No  doubt  Zittel's 
groups  marked  A  and  E  form  excellent  divisions,  but  B,  C,  and  D  comprise 
widely  differing  types,  and  some  of  their  families  include  monocyclic  and 
dicyclic  forms.  As  a  whole,  Zittel's  cla.ssification  marks  a  great  advance 
over  those  of  his  predecessors,  and  he  is  the  first  writer  who  gave  a  good 
definition  of  the  families,  and  who  arranged  them  systematically. 


HISTOUICAL. 


In  1H70,  n  month  or  two  iiftcr  tlio  uppi'mimco  of  von  Zittt'l's  IlMinltnicli, 
wo  piilili^licMl  I'liit  1.  of  our  l{t<vir*ion  of  the  I'alii'ocriiioidL'ii,  utiilinicin^'  tliu 
Iclitliyocriiiiiliu  and  C^utliociiiiitliu  ;  and  in  ISHl  hut  II.,  containing  tliu 
iS|)liiuroidocriniila<.  In  both  parts  wo  gavo  a  lovii'w  of  tho  genera  then 
known,  which  wero  rudu.-<i;riheil  and  M^'^teinalically  arriingcd.  We  al^^o  gave 
witli  each  genus  a  list  of  tlie  Hpucie.s  and  their  synonyms  mo  fur  as  then 
known.  No  elTort  was  niiidu  \>y  lis  to  subdivide  the  tinee  groups,  hecau>e. 
as  wo  thought,  tlio  knowK'dgo  of  fossil  Crinoids  had  not  been  advanced 
snllicicntly  to  justify  it.  Wo  waited  for  tlie  pnbhcation  of  tlio  Challenger 
Keport,  which  wo  hoped  would  solvo  certain  important  morphological 
questions.  It  seemed  to  us  that  a  revi-ion  of  tho  genera,  many  of  which 
had  been  incorrectly,  others  insulhciently,  defined,  and  tho  arranging  of 
them  systematically  among  a  few  largo  natural  groups,  was  prefeial)le  to 
n  classification  based  npon  nnrelialde  data.  Wo  separated  tho  Crinoids  into 
Palivocrinoidea  and  Stoinatocrinoidea,*  tho  latter  to  include  idl  M<sozoic 
and  later  lorms. 

Tho  name  "  I'alivocrinoidea"  had  lieen  introduced  by  Waclisniuth  in 
1877  as  a  subdivision  of  tho  Crinoidea.t  to  include  those  forms  in  which  the 
disk  is  roofed  by  a  second  integument,  which  he  supposed  Id  exist  in  all 
Paliuozoic  Crinoids.  IIo  recognized  among  tho  Palivocrinoidca  three  dif- 
ferent plans :  — 

A.  'I'ho  Ar/iii'iiruiiis  plan :  Tegmon  rigid  ;  composed  of  heavy,  rather 
large,  immovable  plates,  forming  a  free  inch. 

IJ.  Tho  Taxdcriiiiis  i)hin  :  Tegmen  llexible,  consi  ling  of  minute,  movable, 
plates. 

C.  Tho  Cfiiillmrrlnus  phin :  Tegmen  at  tho  four  regular  sides  composed 
of  a  largo  interiaili.d  plate,  tho  posterior  side  extended  into  a  tube  or  sac ; 
mouth  and  food  grooves  covered  by  small  p'ates. 

Tho  diftVrentiation^  in  tho  tegmon  ho  tliought  were  accompanied  by  im- 
portant modifications  in  the  composition  of  the  dorsal  cup,  and  ho  expressed 
the  opinion  that  the  construction  of  the  tegmen  afforded  excellent  charac- 
ters for  subdivisions.  Those  divisions  were  actually  made  by  ns  in  tho 
Revision,  Part  III.,  and  they  form  practically  the  foundation  of  our  present 
chissification,  notwithstanding  that  our  views  respecting  the  tegmon  itself 
Imve  since  then  undergone  considoraljlo  changes. 

•  Tu  plnco  of  Stnmiitnoriiini(lpn  we  afterwards  adopted  Carpenter's  profcral)le  name  "  Ncoeriiuiidea." 
t  His  paper  "On  tli-  C  inslruclioii  of  the  Siiirihiil  and  its  Value  in  Ciassilicatinn."  —  Anicr.  Jour.  Sei. 
and  Arts  (3d  series),  Vul.  XIV.,  September,  18;7. 


26 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


Among  the  questions  discussed  by  us  in  Part  II.,  the  most  perplexing 
one  was  that  respecting  the  orals.  As  these  plates  are  developed  among  the 
fir.'5(  in  the  larva,  it  seemed  to  follow  that  they  must  be  present  also  in  the 
Palaiocrinoidea ;  but  tiie  dilficulty  was  to  determine  which  of  the  various 
plates  in  the  summit  represent  them.  The  median  portion  of  the  tegmen 
in  most  of  those  Crinoids  is  covered  by  from  seven  to  ten  asymmetrically 
arranged,  more  or  less  prominent  plates,  consisting  of  a  central  one  of  larger 
size,  four  otiiors  nearly  as  large  directed  anteriorly,  and  five  others  placed 
posteriorly.  ^.Ve  regarded  the  central  plate  as  an  element  unknown  among 
the  la^or  Crinoids,  which  occurred  only  in  forms  with  a  closed  mouth,  and 
that  it  actually  covered  the  oral  opening.  The  oraLs,  we  thought,  were 
represented  by  six  plates :  four  large  and  two  smaller  ones,  the  two  latter 
jointly  representing  the  posterior  oral,  broken  up  on  account  of  anal  plates. 

Part  111.  of  our  Revision  appeared  in  1885.  It  contains  the  genera  which 
had  not  been  considered  before ;  and  we  also  completely  revised  Parts  I.  and 
II.,  making  important  changes  in  the  classification.  Tiie  Paloeocrinoidea 
were  subdivided  into  three  sub-orders :  the  Camekata,  the  Ix.vduxata,  and 
the  AinicuLATA,  which  we  distinguished  by  the  mode  of  union  between  the 
plates  of  tiie  calyx,  and  the  condition  of  the  arms,  whether  free  above  the 
radials,  or  partly  incorporated  int^o  tiie  cup.  The  origins  of  these  groups 
date  back  to  a  time  of  which  we  have  no  palneontological  I'ecord,  they 
being  already  highly  differentiated  among  the  earliest  known  Crinoids. 
We  divided  them  into  twenty-six  families. 

The  Crinoidni  Camcrata  were  separated  into  Reteocrinidae,  Rhodocrinidoe, 
Tliysanocrinidfc,  Glyptasterida?,  Mclocrinidaj,  Actinocrinidie,  PlatycrinidoD, 
Hexacrinida),  Eucalyptocrinidoe,  Barrandeocrinidto,  and  Acrocrinidfo. 

The  Cn'nohh'a  Ar/iciila/a  were  subdivided  into  Ichthyocrinida)  and  Cro- 
talocrinidcB. 

Tlie  Cnnniilca  Iiifidioiafa  were  subdivided  into;  —  A.  Criiioidm  Lnniformia, 
with  Ilaplocrinidas,  Cupressocrinido3,  Gasterocomida?,  and  Stephanocrinidoc  ; 
B.  Crinnidm  Fidvhila,  with  ITybocrinidao,  Heterocrinidoe,  Anomalocrinidaj, 
BelemnocrinidaL',  Cyathocrinidae,  Calceocrinida?,  Catillocrinida?,  Poteriocri- 
nidoD,  Encrinidfo,  and  Astylocrinidae. 

Most  important  from  a  morphological  point  of  view  was  the  discovery 
of  a  fixed  law  respecting  the  orientation  of  the  stem,  which  enabled  us  to 
tiscertain  the  presence  ot  mfmbasals  in  many  species  in  which  these  plates 
are  hidden  by  the  column.     By  means  of  this  law  we  were  led  to  the  con- 


PI 


HISTORICAL. 


27 


elusion  that  by  far  the  majority  of  the  NoocriiioiJea  are  built  on  the  dicyclic 
plan,  and  either  have  small  infrabasals,  or  had  tliem  in  their  larval  state. 
We  continued  to  u«e  the  term  "vault"  as  opposed  to  disk,  believing  that 
the  tegmen  of  Pahvozoic  Crinoids  differed  morphologically  from  tlie  disk  of 
later  ones.  Respecting  the  oral  question  our  views  had  undergone  consid- 
erable changes,  owing  to  the  discovery  that  the  two  smaller  plates,  which 
we  supposed  represented  together  the  posterior  oral,  are  radially  disposed 
instead  of  interradially,  and  we  inferred  that  the  central  plate  alone  repre- 
sented the  oral  pyramid  of  other  Crinoids,  a  view  afterwards  strongly  con- 
tested by  Dr.  P.  II.  Carpenter. 

In  1884  Carpenter's  Challenger  Report  on  Stalked  Crinoids  came  out, 
and  in  1888  that  on  Comatulo3.  In  the  former  the  author  discussed  among 
other  things  the  morphological  relations  between  Paleozoic  and  Mesozoic 
forms,  and  replied  to  some  points  which  we  had  brought  out  in  the  Revision. 
With  regard  to  the  structure  of  the  tegmen  he  argued  that  some  Platycri- 
nidte  had  a  "vault"  ;  but  that  the  ventral  covering  of  others  did  not  differ 
essentially  from  the  disk  of  the  Neocrinoidea.  He  believed  that  the  Pal- 
aeozoic Crinoids  differed  essentially  from  the  later  ones  by  means  of  their 
irregular  syuuuetry,  caused  by  the  introduction  of  aniil  plates ;  and  upon 
this  and  other  ground-,  to  which  we  allude  in  another  place,  he  made  the 
Palnoozoic  and  later  Crinoids  independent  orders.  In  his  classification  he 
fell  back  upon  Leuckart's  almost  forgotten  name  "Pelmatozoa,"  which  he 
made  a  branch  of  tlie  Echinodermata,  with  Crinoidea,  Blastoidea,  and  Cys- 
tidea  as  classes,  and  tiie  Palajocrinoidea  and  Neocrinoidea  as  orders.  He 
also  discussed  the  oral  question,  adopting  the  view  which  we  had  brought 
out  in  1881,  but  abandoned  in  the  following  year.  He  assumed  that  the 
so-called  central  plate  represents  the  dorso-central  at  the  abactinal  side, 
the  six  proximals  (iiis  orals)  tlie  basiils,  and  that  the  latter  are  homologous 
with  the  genitals  of  the  Urchins.  In  the  second  Challenger  Report,  that 
on  the  Comatula},  we  were  criticised  very  severely  for  asserting  that  prob- 
ably the  Comatula3  had  infrabasals  in  the  larva,  which  were  actually  dis- 
covered by  Bury  before  the  Report  was  published. 

Among  the  many  interesting  papers  written  by  Dr.  P.  II.  Carpenter, 
none  attracted  more  attention  than  the  one  in  which  he  discussed  the  rela- 
tions of  the  basals  in  monocyclic  and  dicyclic  Crinoids.*     He  proved  that 


383). 


Oil  the  "  Oral "  ami  Apical  Systems  of  Echiuodcrms  (Quart.  Journ.  of  Microsc.  Sci.,  1878,  pp.  351- 


28 


THE  CKINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


- 1 


il 


the  proximal  ring  of  the  latter  represents  an  independent  element,  and  that 
their  second  ring  of  plates  corresponds  morphologically  to  the  proximal  one 
m  monocyclic  forms.  This  is  now  accepted  by  almost  every  writer.  Another 
important  contribution  to  the  knowledge  of  Crinoids  was  made  by  a  paper 
on  Allugecrinus*  a  Carboniferous  genus,  in  which  the  ventral  surface  is  cov- 
ered completely  by  live  oral  plates,  thus  retaining  persistently  the  structure 
of  tiio  Aiih'don  larva. 

The  progress  in  tlie  knowledge  of  fossil  Crinoids  was  paralleled  by  that 
among  recent  ones,  of  wliicli  a  great  number  of  new  forms  were  obtained  by 
the  dredging  expeditions.  Until  about  18G0  we  possessed  of  Stalked  Cri- 
noids only  a  few  specimens  of  Pciihwnnus  caput-iiicdnsa,  and  one  or  two  of 
Iloloptis  Ihtivsoni ;  but  since  then  new  discoveries  followed  in  rapid  succes- 
sion. In  18G4,  Sars  described  the  genus  li/ikocn'inis  ;  Jeffreys,  in  1872,  a 
new  species  of  Peiitacrimis  from  the  Bay  of  Biscay  ;  de  Pourtales,  in  1874, 
a  second  species  of  Rhi-ocrimis.  The  dredgings  by  the  '•  Blake  "  under  the 
supervision  of  A.  Agassis  in  tiic  Gulf  of  Mexico  brought  to  ligiit  the  new 
Comatulid  genus  Atclecriinm,  and  a  large  number  of  specimens  of  PcnUi- 
criiius ;  those  of  the  "Albatross"  in  1891,  off  the  Galapagos  Islands,  the 
remarkable  genus  Culdiiiocriinis.  The  largest  results,  however,  were  obtained 
by  the  "Challenger"  expedition,  which  produced  tluee  new  genera  of 
Stalked  Crinoids,  and  one  of  Comatulaj.  Progress  in  morphology  and  em- 
bryology in  later  years  has  been  as  rapid  as  the  discovery  of  now  species; 
in  proof  of  which  we  need  only  refer  to  the  works  of  Allinan.  Goette,  Sars, 
Greeff,  Ludwig,  Pourtales,  Bell,  Barrois,  W.  B.  Carpenter.  Wyville  Thomson, 
Perrier,  Bury,  P.  II.  Carpenter,  Vogt  and  Yung,  and  A.  Agassiz. 

Tiie  oral  question  was  finally  solved  in  1888  t  by  our  di  overy  of  the 
remarkable  specimen  of  Taxocrlnm,  which  proved  conclusively  that  in  forms 
with  large  plates  around  the  oral  centre,  asymmetrically  arranged,  the  orals 
are  repros-ented  not  by  the  central  plate  alone,  as  we  had  supposed,  nor  by 
the  four  large  and  two  smaller  proximals,  as  claimed  by  Dr.  (Carpenter,  but 
by  the  so-called  central  plate  together  with  the  foui  large  proximals ;  the 
disturbance  in  the  arrangement  of  tlie  plates  being  due  to  the  introduction 
of  anal  plates.     It  was  further  proved  that  in  specimens  in  which  the  whole 


r 


i^ 


*  Oil  Allagocrinns,  tlio  Rppresoiilntive  of  a  new  family,  etc.  By  P.  II.  Cavpeiilcr  and  R.  Ellicridgo,  Jr. 
(Ann.  niid  Mag.  Nat.  His.,  April,  ISSl,  pp.  2S1-297). 

t  Discovery  nf  llic  Ventral  SInictnre  nf  Taxncriniis  and  Ilaploeriniis,  and  Conseqnent  Modifieatlous  in 
tlic  Classifiealion  nf  llie  Crinoidea ;  by  Charles  Waclismuth  and  Frank  Spring'  v  (Proceed.  Acad.  Nat  Sci. 
Pliila.,  ISSS,  pp.  s.^iz-aci). 


I 


L 


HISTORICAL. 


29 


T 


tegmen  consists  of  five  large  pieces,  as  in  Ilaplocriuits,  etc.,  these  plates  are 
ornls,  and  not  siippleinentiiry  pieces  as  we  had  supposed. 

The  logical  consequences  of  these  conclusions  were  taken  up  by  us  in 
1890,*  when  we  undertook  to  prove  that  the  so-called  vault  of  Paheozoic 
Crinoids  is  not  a  structure  siti  (jciterh,  but  a  highly  differentiated  disk  ;  that 
their  large,  rather  regularly  arranged  interbrachial  and  iuteraml)ulncral 
plates  represent  morphologically  the  smaller  irregular  pieces  between  tlie 
rays  and  ambulacra  of  later  forms,  and  that  the  Paleozoic  and  Neozoic 
Crinoids  do  not  differ  so  e-isentially  fronx  one  another  as  we  had  supposed. 
It  also  appeared  that  neitlior  the  closure  of  mouth  and  food  grooves,  nor 
the  presence  of  anal  plates,  is  a  constant  character  among  the  older  Cri- 
noids, and  we  were  compelled  in  1888  to  abandon  the  Pala^ocrinoidea  and 
Neocrinoidea  as  systematic  groups. 

That  the  two  groups  could  not  be  upheld,  was  proved  also  by  Neumayr,t 
who  claimed  that  none  of  the  characters  by  which  they  had  been  separated 
was  persistent ;  and  he  [jroposed  in  place  of  them  a  primary  divif<ion  based 
upon  the  condition  of  the  month  and  ambidacra,  whether  mbU'jiHindl  or 
siipndcgminal,  viz. : 

I.   Hijpasoocrlno'uleii.     JFouth,  ambulacral  vessels,  anil  Saumpliittclieii  (the  liittor  if  pres- 
ent) beneath  the  tegnion. 

1.  Sjiliwroit/ocriiKiren.     Cup  mostly,  tegmen  always,  construetoil  of  a  largo  number  of 

plates  immovably  connected  among  themselves.  Generally  several  of  the  arm 
plates  incorpotiited  into  the  calyx  by  means  of  interrailial  pieces,  Tegmen  roof- 
ing the  whole  ventral  surface.  Among  its  plates  are  readily  distinguished  a 
central  one,  and  four  and  two  interradiul  proximals.  Anus  either  directly  piercing 
the  tegmen,  or  pl.aced  at  the  terminal  end  of  a  plated  tube.  (This  group  agrees 
with  our  Camerata.) 

2.  JIdjilocrinacea.     Cup  and  tegmen  composed  of  a  small  number  of  immovable  jiieces. 

The  former  having  but  one  radial,  and  no  interradials  except  an  anal.  Tegmen 
with  a  central  plate.     (Our  Larvifonnia.) 

3.  Jf/tt/iyncrliiacca.     Cup  and  tegmen  composed  of  very  numerous,  somewhac  movable 

pieces;  the  former  having  two  basal  rings  and  more  than  one  ordei-  of  radials. 
(Our  Ichthyocrinida'.) 
II.  Epascofrinoiilea.  Ambulacra  not  covered  by  the  tegmen;  their  furrows  exposed  or 
closed  by  Satimpliittchen. 
1.  Ci/itlhocrlnacfa.  I?ase  generally  dicyclic.  Cup  without  interradials  nt  the  four 
regular  sides.  Tegmen,  so  far  as  known,  composed  of  five  orals,  whieli  sujiport  at 
their  edges  the  ambulacra;  the  latter  covered  by  Saumpliittchen.  Anus  within  the 
ventr.al  sac.     (Our  Fistulata.) 

•  Pprisomlc  rialcs  of  the  Crinoids  (Proceed.  Acad.  Nat.  Sci.  Pliila.,  October,  1S90,  pp.  .?t5-375). 
t  Dio  Sliimme  des  Tiierreiclics,  Wicn  und Prng,  1889,  pp.  438-lCO. 


30 


THE  CRINOIDEA  CAMEKATA  OF  XOKTII   AMElilCA. 


2.  Pentiicrlnucea.  Calyx  with  a  well  ilofiiicil  basal  ring;  iiifrabasals  wanting  or  rudi- 
mentary. Ainbulacral  furrows  and  mouth  (in  all  of  tlii'ni '.')  exposed.  Tegmen 
pliable  with  movable  Saunii>liiltelien,  or  witli  five  huge  orals  and  without  Saum- 
pliittchen.  (I'entaerinida',  Apioorinidie,  riieatocrinida.',  Uourguetocrinida',  Kiigenia- 
crinidiL',  Ilolopidie,  and  Comatulidie.) 

Neuinnyr's  primary  divisions  are  partly  based  upon  incorroct  observation. 
Among  the  three  groiip.s  which  he  refers  to  the  llypascocriiioidea,  the 
Saumpliittchen  are  siibtegniinal  only  in  the  Ilaplocrinacea.  In  the  remain- 
ing groups  they  may  be  subti^gminal  or  exjiosed  among  .sjiccies  of  the 
same  genus.  The  Ichthyocrinacea  even  have  an  open  mouth  and  open 
food  grooves.  On  the  oral  question  he  agreed  with  Carpenter,  and  took 
the  six  proximals  to  be  representatives  of  the  orals. 

Neumayr  ranked  the  Crinoidea,  Blastoidea,  and  Cystidea  as  independent 
classes,  and  believed  that  the  two  former  are  derived  from  the  C3stidea, 
which  to  some  extent  combined  the  characters  of  the  three  groups. 

Dr.  Steinmann  *  adopted  our  classification  of  1885,  with  Pakeocrinoidea 
and  Neocrinoidea  as  primary  groups. 

Two  other  classifications  were  proposed  in  America,  —  one  by  Prof. 
E.  J.  Chapman,  the  other  by  S.  A.  Miller.  The  former  t  is  to  a  large 
extent  hypothetical,  being  founded  upon  characters  of  which  nothing,  or 
almost  nothing,  is  known  among  Pakvozoic  Crinoids.  His  classification  is 
based  mainly  upon  the  presence  or  absence  of  a  canaliculation  within  the 
calyx  and  arm  plates  for  the  occupation  of  axial  cords.  He  recognizes 
three  leading  divisions  :  — 

1.   EincdiiUata.     Calyx  plates  and  arm  plates  without  internal  canals. 
II.   Fis/iilata.     Arm  plates  with  donsal  canal.     Cal^x  plates  imperfoiate. 
in.    CaiHtUculiita.     Calyx  plates  traver.-ed  from  the  basals  upwards  by 
delicate  radiating  canals.     The  arm  plates  canaliferous  dorsally. 

The  classification  of  S.  A.  Miller  J  may  perhnps  facilitate  elementary 
studies,  but  has  no  value  from  a  morphological  point  of  view.  In  forming 
his  families  he  made  the  number  of  basals  the  most  important  character  for 
division,  next  the  presence  or  absence  of  "  subradials,"  and  after  this  the 
structure  of  the  "azygoiis  side  and  other  parts."  His  classification  is  a 
reminiscence  of  that  of  Angidin,  §  who  divided  the  Swedish  Crinoids  into 

•  Elcmente  der  Pnltpoiitnloi^ie,  Loipzip,  ISSS. 

t  A  Clnssificrttion  of  Crinoids,  bv  Professor  E.  J.  riiapmnn,  Toronto.  ]882. 
X  Amcrioan  Gi'olnsist.  Vol.  VI..  1S90,  pp.  275-2SC,  and  pp.  340-35?. 
§  Iconogr.  Crinoid.  Suecitp,  1S7S. 


'4!i 


HISTORICAL. 


31 


Trlmern,  Tetramera,  Pontamein,  and  Polymura.  The  fallacy  of  this  plan  is 
well  shown  if  we  consider  that  the  smaller  number  of  basals  is  simply  the 
result  of  anchylosis  of  two  or  more  of  the  original  live  plates;  and  tliat  in 
many  cases  it  brings  together  the  most  diverse  forms,  while  forms  which 
naturally  belong  together  are  widely  separated.  We  need  only  refer  to 
the  highly  differentiated  Calceocrinidiu,  of  which  some  species  have  four 
basals,  and  others  but  three.  In  the  genus  Plaljemnis  the  normal  i.unnber 
is  three;  but  in  many  cases  they  are  anchylosed  into  a  solid  disk,  leaving 
no  trace  of  suture  lines.  Under  Miller's  classification  many  species,  and 
often  individuals  of  the  same  species,  would  have  to  be  referred  to  different 
families. 

The  most  important  recent  European  writings  on  Palaeozoic  Crinoids  are 
those  of  Mr.  F.  A.  Bather  of  the  British  Museum,  who  has  done  much 
valuable  work  in  systematizing  the  terminology.  His  descriptive  work  has 
been  chiefly  confined  to  the  Fistulata  of  the  Wenlock  limestone  of  England, 
and  its  equivalent  in  Sweden ;  but  we  should  like  to  see  it  extended  to 
include  the  Carboniferous  Crinoids  of  England,  of  which  careful  study  is 
greatly  needed.  His  admirable  Monograph  on  the  Crinoidea  of  Gotland, 
Part  I.,*  arrived  too  late  to  be  considered  in  this  work  as  fully  a.^  would  be 
desirable  ;  in  it,  however,  he  has  rendered  a  great  service  to  all  students  by 
bringing  order  out  of  the  confusion  in  which  the  splendid  Swedish  collec- 
tions had  become  involved  by  reason  of  Angelin's  fictitious  illustrations  and 
restorations.  We  hope  nothing  will  occur  to  prevent  the  completion  of 
his  work. 


*  "  The  Criuoidca  luatluiiata,"  with  ten  photograpliic  jilutes,  published  by  the  Royal  Swedish  Academy 
of  Sciences. 


ii 


II.    TERMINOLOGY. 

The  following  terminology  niny  be  regnnletl  as  the  result  of  a  two  years' 
conesponlence  with  the  late  Dr.  P.  II.  Carpenter,  carried  or  with  a  view 
to  securing  greater  uniformity  and  preciision  in  the  morphological  nomen- 
clature of  the  Crinoids;  and  we  mutually  agreed  to  adopt  it  in  our  future 
writings.  On  some  points,  Dr.  Carpenter  defined  his  own  position  in  a  paper 
whii'li  ai)peared  about  a  year  before  his  death.* 

Mr.  F.  A.  Bather,  in  1890,  alsof  agreed  to  accept  this  terminology  with 
very  slight  modifications,  and  applied  it  practically  in  his  earlier  descriptions 
of  British  fossil  Crinoids,  but  renounced  it  in  18U2,|  and  proposed  in  its 
place  a  now  one,  which  will  be  discu.ssed  later  on.  Many  of  the  terms  which 
are  explained  below  are  familiar  to  every  studo^t  of  Crinoids ;  but  as  some 
of  them  have  been  used  in  dilYcrent  senses  by  different  authors,  we  include 
them  for  the  sake  of  completeness.  A  few  of  theni  are  new;  others,  though 
used  by  foreign  authors,  have  never  been  introduced  in  American  Crinoid 
literature.  We  believe  that  the  terms  are  adapted  equally  well  for  the 
description  of  recent  and  fossil  Crinoids,  ]»innulatc  as  well  as  non-pinnidate. 
There  are  a  few  additional  terms,  not  of  such  general  application,  which 
will  be  found  explained  in  their  proper  places. 

The  Crinoids,  Blastoids  and  Cystids,  -with  perhaps  a  few  exceptions, 
differ  from  all  other  Echiuoderms  in  being  at  some  stage  of  their  life  pro- 
vided with  a  stem  for  attachment  to  other  objects.  This  structure  gives 
rise  to  a  difl'erenco  in  habit,  l)y  which  they  live  upon  the  aboral  side,  instead 
of  creeping  about  mouth  downward  in  search  of  food. 

The  skeleton  or  test  of  a  Crinoid  consists  of  the  ftcm  or  column,  and  the 
cro/fii.  If  the  stem  is  provided  with  lateral  appendages,  these  are  called 
cirri.  Those  of  the  distal  end  are  the  rmliciikir  cirri,  and  form  the  root. 
The  stem  is  constructed  of  the  stem  joints,  of  which  the  larger,  and  all  cirrus- 

•  "Oil  some  Points  ill  tlie  Anatomical  Nonicnpl;iturcof  tlic  Kcliiiiodcrms  ;  "  Ann.  and  ^^ag.  Nat  lliji., 
1890  (July  number). 

+  Uritisli  Fossil  Crinoiils;  ibid.  (Apiil  iniiiiboi),  jip,  300  to  H:iO. 

J  Sngijcsted  Terms  in  Crinoid  Moi'iibolngj- ;  ibid.  (January),  pp.  51-C6 


~1 


'-3h. 


TERMINOLOGY. 


33 


bearing  ones,  constitute  the  nodal  joints,  and  tliose  interposed  between  them 
the  inlcrnudd ]omis.  The  term  dorsocenlml  is  used  for  the  enhirged  terniiniil 
joint  of  the  stem,  by  whiclj  the  young  Crinoid  is  attached  to  other  objects; 
and  cenlrodorsid  for  the  modified,  cirrus-bearing  top  joint  of  the  Conlatula^ 
us  well  as  for  the  plate  within  the  infrabasal  ring  of  the  JIarsupitidie.  The 
longitudinal  canal,  passing  through  the  centre  of  the  stem,  is  the  axiid  ciimd. 
In  speaking  of  the  form  of  the  stem,  allusion  is  made  to  the  transverse 
section. 

The  crotvn  consists  of  adi/x  and  arms ;  the  former  encloses  the  visceral 
cavity;  the  latter  constitute  tlie  free  appendages,  passing  off  from,  and  con- 
necting with  the  calyx. 

The  ctdi/x  is  composed  of  the  dorsal  cu}>,  and  the  ventral  did-  or  teamen,  the 
arm  regions  forming  tlie  line  of  demarkation  between  them.  The  dorsal 
cup  conforms  in  a  general  way  to  the  apical  or  abactinal  system  of  the 
Echinoderms,  the  ventral  disk  to  the  oral  or  actinal  sj'stem. 

The  dorsal  cup,  in  its  simpler  form,  is  constructed  of  hasnls,  infralasah, 
when  present,  and  radials ;  to  which  must  be  added  the  amd  plates,  wJiich. 
however,  are  not  always  represented.  In  the  more  complex  form  it  includes 
also  some  of  the  lower  brachials,  which  have  been  incorporated  into  the 
walls,  either  by  lateral  union  among  themselves,  or  by  means  of  interradial 
and  interaxillary  plates ;  the  last  mentioned  plates,  in  that  case,  also  form- 
ing part  of  the  cup.  All  Crinoids  belonging  to  the  simpler  form  are  dis- 
tinguished as  Crinoklca  Inadunuia ;  those  of  complex  form,  ivhcn  the  caf>/x  is 
rigid,  as  Crinoidca  Camc-a/a,  but  when  Jkxible,  as  Crinoidca  Artiadata. 

The  base,  or  part  next  to  the  column,  may  be  composed  of  one  or  two 
rings  of  plates,  which  are  distinguished  as  hasals  and  iii/rahasals.  The  basals 
adjoin  the  radials  and  alternate  witli  them,  being  interradial  in  position. 
The  infrabasals,  when  present,  are  radially  disposed  below  the  basals.  Cri- 
noids in  which  the  base  consists  of  a  single  ring  of  plates  are  called  mono- 
cyclic  ;  those  with  two  rings,  dicijclic. 

The  radials  consist  of  the  first  plate  of  each  ray,  and  all  plates  beyond 
this  in  radial  succession  are  brachials;  fixed  brachials  so  far  as  they  take 
part  in  the  calyx, /rcc  brachials  or  arm  pla/cs  when  they  do  not.  In  some  of 
the  earlier  Crinoids  one  or  more  of  the  radials  are  bi.sected  transversely,  in 
which  case  the  two  parts  are  distinguished  as  stipcr-radials  and  iiifcr-nidials. 

The  arms  may  be  simple  or  branching.  When  the  divisions  are  of  equal 
siie,  and  rise  to  the  same  general  height,  they  are  regarded  as  parts  of  the 


34 


THE  CRINOIDEA  CAMERATA  OF  NORTH   AMERICA. 


arms  jjro/wr ;  but  when  siimllcr  niiJ  shorter  than  tlie  main  arms,  they  nre 
eiilled  uniUels.  It"  there  are  small  hiteral  appentlayes,  given  off  alternately 
from  opposite  sides  of  the  arms,  they  receive  the  name  pinnules.  The  arms 
are  imiavmU  when  their  joints  extend  through  to  both  sides  of  the  arm ; 
bmri'al  when  they  do  not,  but  interlock  from  opposite  sides. 

The  brachials  succeeding  the  radials  (the  lirst  axillary  included),  whether 
free  or  fixed,  are  called  coduls,  or  primary  brachials ;  tho.se  of  the  second 
order  dislichuk,  or  sceoiiiliri/  brachials;  those  of  a  third  order  2>nlmars ;  and 
all  succeeding  brachials,  wiiether  there  are  additional  divisions  in  the  ray 
or  not,  receive  the  imxno  posl-paliiiars.  When  in  the  description  of  a  species 
it  is  noces.sary  to  specify  any  of  these  plates,  they  are  distinguished  as 
brachials  of  the  fourth,  fifth,  or  sixth  order,  and  so  on  to  the  last  bifiuvation. 
We  also  find  it  convenient  occasionally  to  refer  to  them  as  the  plates  be- 
yond the  fourth,  fifth,  or  sixth  axillary ;  or,  when  free,  as  plates  of  the  first, 
second,  or  third  division  of  the  arms.  The  plates  of  the  different  orders, 
according  to  their  rank,  are  distinguished  as  first,  second,  or  third  costals, 
distichals,  palmars,  etc.,  and  the  bifurcating  plates  as  the  (uilhirics  of  their 
respective  order.i.  All  these  appellations,  however,  are  not  applied  to  the 
divisions  formed  by  the  armlets  and  pinnules,  although  the  plates  which 
support  them  are  in  fact  axillary,  and  each  armlet  or  pimiule  is  morpho- 
logically the  homologue  of  a  whole  dicliotom. 

When  two  or  more  arm  joints  meet  transversely  by  a  rigid  suture,  and 
only  the  upper  onj  is  pinnule-bearing,  those  joints  form  a  si/zi/ffi/,  whether 
the  apposed  faces  are  r.idiated,  dotted,  or  smooth;  the  lower  joint  bearing 
no  pinnule  is  called  the  /////w^y^«/ joint,  the  upper  one  the  finznaal. 

T'e  spaces  between  the  rays  and  their  subdivisions  are  filled  by  supple- 
mentary plates.  Those  between  the  rays  proper  are  designated  by  the 
general  term  hitcrradink,  whether  they  belong  to  the  dorsal  cup  or  to 
the  ventral  disk.  Those  of  the  dorsal  cup,  which  arc  interposed  between  the 
brachials,  are  distinguished  as  iuierhraclmls,  and  those  of  the  ventral  disk, 
which  lie  between  the  ambulacrn,  as  intcramhnhcraU.  Plates  between  the 
radials  at  all  five  sides  are  only  foimd  in  dicyclic  Crinoids,  but  in  most  of 
the  PalcTOzoic  Crinoids  there  are  one  or  more  such  plates  at  the  posterior 
side  —  the  .so-called  amd  plates. 

The  anal  plates  form  the  base  of  the  anal  structures,  and  consist  of  the 
special  or  frst  anal  plate,  which,  when  present,  invariably  rests  upon  the 
truncated  upper  face  of  the  posterior  basal,  and  between  two  radials.     Most 


Ill 


TEUMIXULOGY. 


86 


of  the  Camerata  also  linvo  auxiliary  nnul  plates,  which  may  be  present  even 
wiieii  the  special  anal  is  wanting;  tiiey  are  interposed  between  the  inter- 
brachials,  following  the  median  line  of  the  posterior  area.  Another  plate, 
the  so-called  "  second  anal  plate  "  of  American  authors,  which  only  occurs 
in  the  Inadunata  and  Articulata,  is  now  called  the  mdiuiml.  It  rests  within 
the  re-entering  angle  of  two  adjoining  basals  to  the  right  of  the  first  anal 
plate,  and  is  the  lower  half  of  a  bisected  radial,  whicii  owXy  in  some  genera 
assumes  anal  functions. 

Certain  groups  have  interaxillary  plates,  which  occupy  the  spoces  within 
the  axil  of  the  disticlmls  and  palmars ;  the  plates  between  the  former  are 
the  iiitenU4ii'Jutls  ;  those  l)etwocn  the  latter  the  intcrpdlmars. 

The  ventral  disk  embraces  the  disk  ambulacra,  the  mouth,  and  the  anus. 
It  is  formed  by  tlie  omls,  the  anihtdacml  and  inlcmmhulucml  plates.  The 
posterior  side  of  the  disk  in  certain  forms  of  the  Inadunata,  to  which  wo 
have  given  the  name  Luiduiiakt  Fisluhda  is  extended  upward  into  a  large  sac 
or  tube,  which  is  called  the  vcntml  sac  or  vcntml  tiihe.  This  tube  is  frequently 
perforated  by  pores  or  slits,  which  probably  promoted  respiration.  Other 
forms  of  that  group  do  not  have  these  pores  through  the  sac,  but  have 
a  single,  rather  large,  profusely  perforated  plate  upon  the  disk  proper,  be- 
tween the  sac  and  the  mouth,  —  the  so-called  iiiadrcjwri/c.  The  disk  in  most 
of  the  Camerata  has  small  rcspiralori/  pores  or  .«lits  near  the  arm  ba.se.s,  pierc- 
ing the  sides  of  the  plates.  In  recent  Crinoids,  ond  probably  in  the  Articu- 
lata generally,  in  which  the  pores  penetrate  the  body  of  the  plates,  the 
perforated  plates  have  received  the  name  aii-amhtilacrals. 

The  anus  is  interradial  in  position ;  its  opening  may  be  cither  central, 
subcentral,  excentric  or  marginal ;  placed  at  the  distal  end  of  a  tube,  or 
opening  directly  through  the  disk. 

The  "amd"  tube  must  not  be  confounded  with  the  "  ventral"  tube  of  the 
Fistulata,  which  often  does  not  contain  the  anus,  but  when  it  does,  the 
opening  is  generally  on  the  anterior  side. 

The  mouth  occupies  the  centre  of  radiation,  and  is  tegminal  or  srditegminal. 
If  it  is  tegminal,  the  opening  is  surrounded  either  by  the  orals  and  the  ends 
of  the  ambulacra,  or,  when  the  orals  are  absent,  by  interambulacral  plates, 
which  form  a  lip  around  it.  H sultcgminol,  it  is  completely  closed,  either  by 
the  orals  or  interambulacral  plates,  which  form  a  roof  over  it. 

The  ambulacra  diverge  from  the  mouth  to  the  tips  of  the  rays,  following 
the  ventral  furrows  of  arms  and  pinnules.    When  sub  tegminal,  they  enter 


36 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


CT^'. 


the  cftlyx  by  inonns  of  the  amhulacnd  or  arm  npenings  at  tlio  upper  cdgo  of 
the  dorsal  cup ;  when  toj^iuinul,  they  follow  the  surfiieo  of  the  disk.  They 
contain  the  ftxiil-jroare,  the  Kinhiildeml  vvusvlx,  the  oi'iiriun  tube,  and  the  (O'hil 
ciiiiiil.  The  fofxf-ffnioi'c  forms  the  upper  passngo.  It  is  followed  in  descending 
Older  by  the  siili/eii/nciilur  canal,  the  (jciillal  canal,  and  the  u.rhil  canal.  The 
axial  canal  contains  the  axial  cords,  which  cominnnieato  with  the  vhambvnd 
ori/an  at  the  dorso-central  basin  of  the  calyx.  The  axial  canals,  in  most  of 
the  Pala)ozoic  Crinoids  permanently,  and  in  the  Aiiledun  larva  temporarily, 
are  mere  grooves  at  the  bottom  of  the  ventral  furrow,  but  in  the  mature 
recent  Crinoid,  and  in  a  few  Palieocrinoidea,  are  separated  from  the  furrow 
by  a  limestone  partition. 

The  aiukdacral  plates  consist  of  the  ud-andmlacral  rr  sidc-invccs,  nnd  the 
corcrixg  plates,  or  Samnpliittchen ;  the  former,  when  present,  constitute  the 
outer,  the  latter  the  inner  rows  of  the  plates.  The  covering  pieces  form 
a  roof  over  the  food  grooves,  and  arc  generally  represented  by  two  alternat- 
ing rows  of  small,  more  or  less  regularly  arranged  plates,  which  in  all 
Crinoids  are  movable  upon  the  arms  and  pinnules,  but  upon  the  disk  only 
in  those  in  which  the  mouth  is  exposed.  In  some  of  the  Cnmerata  the 
plates  are  so  higidy  differentiated,  that  they  have  been  regarded  as  alto- 
gether difTerent  structures,  and  were  called  radial  dome  plates.  We  retain 
this  name  as  a  conventional  term  for  the  large  isolated  plates  of  that  group 
to  distinguish  them  conveniently  from  the  ordinary  covering  pieces. 

The  orals  consist  of  the  five  large  interradial  plates  which  surround  the 
mouth  or  cover  it,  aiul  are  either  symmetrical  or  asymmetrical.  They  are 
symmetrical  when  of  nearly  the  same  size  nnd  form ;  asymmetrical  when 
the  posterior  plate  is  pushed  in  between  the  other  four.  In  some  species 
they  occnpy  the  entire  ventral  surface  of  the  calyx  ;  in  others,  only  a  com- 
paratively small  space  in  the  middle ;  or  they  may  be  completely  resorbed 
in  the  mature  individual. 

The  interamfi'lacral  plates  occupy  the  spoces  between  the  ambulacra, 
their  main  trunks  as  well  as  their  branches.  We  also  apply  the  term  to  the 
platen  covering  the  ambulacra,  and  to  those  encroaching  upon  them  from  the 
sides,  as  in  many  species  of  the  Camerata  In  which  the  disk  ambulacra  are 
subtegminal  or  partly  so. 

The  term  jwrisomic  plales  is  given  to  all  plates  which  are  originally  devel- 
oped from  simple,  cribiform  films  of  limestone.  They  comprise  the  inter- 
radials  and  interaxillaries,  the  anal.'*,  and  all  ambulacral  and  interambulacral 
plates. 


■amvi-.i  -|~~i"  i|ii 


\ 


TKKMINOLOr.Y. 


87 


Tlio  pliitcs  of  a  Crino'ul  nro  imitiMl  cither  hy  suture  or  hy  mu,-<cMilar 
nrtieuliitioii.  Tlie  former  may  be  a  c/wc  suture,  a /w«(' xuturo,  or  au  innliii- 
Inm'ti.  A  close  suture  is  neiuly  or  perfectly  rigid  ;  the  npposeil  faces  are  flat, 
ami  may  be  Hinoolh  or  striated.  In  a  loose  suture  the  faces  are  more  or  loss 
oonravo  or  excavated,  lodging  bundles  of  ligament,  so  as  to  give  to  the 
plates  a  considcral)Ie  amoiuit  of  mobility.  An  anchylosis  is  a  niodilicd  close 
.suture,  in  which  the  lines  of  union  have  been  obliterated  by  subseriuent 
limestone  deposit.  In  a.  muscular  articulation,  the  apposed  faces  are  per- 
forated, and  provided  with  a  transverse  ridge,  or  a  sort  of  ball-aiid-.soeket 
joint. 

The  orientation  is  based  upon  the  natural  position  of  the  Crinoid,  /.  p., 
the  arms  uppermost,  viewing  the  specimen  from  the  anal  side.  The  anal 
interradius  will  then  be  posterior,  the  radius  o])posito  to  it  anterior,  and 
right  and  left  will  correspond  with  the  right  and  left  of  the  observer.  Next 
to  the  anterior  ray  are  the  two  antero-laternl  rays,*  and  adjoining  the  anal 
interradius  the  right  and  left  posterior  rny.s.  Corresponding  appellations  are 
applied  to  the  interradial  spaces,  which  consist  of  the  two  anterior,  the  two 
antero-lateral,  and  the  posterior  or  anal,  interradii. 

In  illustrating  the  plate.?  of  the  calyx,  the  dorsal  view  is  figured  with  the 
anal  intciradius  (7),  and  the  ventral  view  with  the  anal  side  (hucii.  Right  and 
left  remain  the  same  in  both  cases. 

The  tcrmi^  j>ri).ii)ii((l  am]  (lix/n/  m-c  reckoned  from  the  chambered  organ,  so 
that  the  infrabasals  and  the  top-atom-joint  arc  the  proximal  elements  of 
crown  and  stem  respectively.  In  the  crown,  the  outer  surface  of  a  plate 
represents  the  dorsal  side,  its  lower  edge  the  proximal  face,  its  upper  edge 
the  distal  face,  and  the  faces  at  the  sides  are  the  lateral  faces.  In  the  stem, 
however,  the  x/ipcr  face  is  the  proximal,  and  the  lower  one  the  distal. 

•  Those  rnys  nro  called  by  Mr.  Patlicr  t)ic  ri(,'lit  ftiul  left  "anterior"  rays.  The  term  is  ohjeclioiiahlc 
because  we  have  already  the  anterior  ray  proper. 


MOUniOLOCJICAL    PAKT. 


riUMAIlY    AND    sriMTJlMllXTARY    I'LATK.S. 

Tin:  iihites  of  the  Crinoiils  full  initiimlly  into  two  cntogorifM,  viz.,  prlntun/ 
l)Iates,  tiiiil  nccKiiiltri/  ov  mi/>j)liiiini/tin/  pIiitoH.  TIr-  priiimry  plates  nrc  tlic  fii'Mt 
paitn  tlovL'lopcil  in  tliu  larva.  Tliey  are  ifprcMoiitt'd  in  cvoiy  group  of  tlio 
cIuHH,  iiud  luulorgo  comparatively  few  niotlificationH  in  geological  time.  The 
Biippleniontary  pieces  appear  in  the  growing  Crinoiil,  but  arc  nnroprcHenteil 
:i:  .xoiiie  of  the  groups.  Tiiey  are  interposed  between  tlio  primory  plates, 
nnd  help  to  increase  the  capacity  of  the  visceral  cavity.  Tiiey  are  very  im- 
portant in  point  of  classification,  offering  by  their  presence  or  al)sonco,  their 
position  ami  distribution  in  the  caly.v,  their  arrangement  and  multiplication, 
excellent  criteria  for  natural  divisions. 

The  primary  plates  may  be  subdivided  into  two  classes  :  plates  of  the 
abiictinal  system,  and  plates  of  the  actinal  system.  The  former  are  developed 
on  the  rigiit  larval  antimer,  and  include  all  plates  connected  with  the  cham- 
bereil  organ  and  the  axial  cord.s.  The  latter  are  developed  on  the  left  anti- 
mer, and  connnunicato  with  the  mouth  and  the  annular  vessels  surrounding 
it.  The  abactinal  plates  are  represented  by  the  stem  joints,  the  basals, 
iiifrabasals,  radials,  and  the  plates  forming  the  dorsal  parts  of  arms  nnd 
pinnules  ;  the  actinal  plates  by  the  orals  and  anibulacral  plates  to  the  ends 
of  the  brachial  appendages.  The  remaining  plates  will  be  treated  by  us  as 
supplementary  pieces. 


I.    THE   PLATES   OF    THE    ABACTIXAL    SYSTEM. 

A.     Hie  Stan  and  t'fa  Appcmhges. 

The  length  of  the  stem  in  some  Mcsozoic  Crinolds  must  have  been  enor- 
mous. Quenstedt  traced  that  of  a  Jura.ssic  PviUacriints  to  70  feet  without 
reaching  either  end.  This  is  in  striking  contrast  to  its  length  in  Palaeozoic 
forms.     Among  them  the  two  longest  stems  observed  by  us  have  a  length  of 


i; 


MoRi'iroLoorr.vTi  paut. 


89 


/ 


nhoiit  tlirco  feet, — one,  not  <|uite  complete,  being  tliiit  of  a  liirgc  MiylKlin'mim 
/■Jniiiti,  tlio  other,  wliieli  in  perfect,  of  a  S/rnfniriiiiin  irgnlls,  two  of  tlic  liirgcst 
known  Mpecii's.  Tliiit  seems  to  liiivo  been  iilioiit  the  miixiimim  h'iij.Mli.  ami 
it  iniiy  1)0  siiffly  iisMerted  thiit  the  Htem  in  the  miijorily  of  the  oMer  (VimtiilH 
wiiH  not  miieli  over  ii  foot  long.  Homu  Htems  arc  proporlioniilly  wifh-r  nt  I  In- 
top,  iiml  taper  all  the  way  to  tho  root;  others  are  larger  at  the  ili«tiil  enil 
than  at  the  proximal ;  whilu  Htill  others  are  widest  in   the  miilille. 

The  root  is  even  more  variable.  Its  form  was  I'vidently  aci'oimiiodiiled 
to  the  comlitions  of  the  place  of  its  attachment.  When  attached  to  a  solid 
sub.stanco,  it  wa.s  flattened  at  the  distal  face,  Hio  radicular  cirri  sprending 
out  horizontally  ;  but  when  growing  on  an  oo/y  bottom,  it  gave  oil'  long 
vertical  and  lateral  branches,  entering  the  mud. 

The  stem  is  either  circular,  elliptic,  pentangular,  Rtellnte,  semiluuato,  or 
quadrangular,  changing  from  angular  to  round  on  approaching  the  root.  It  is 
composed  of  joints,  which  vary  often  ccjusiderably  in  size.  Certain  of  these 
joints,  which  have  boon  denominated  "  nodal  "  joint,s,  are  separated  from  each 
other  by  intervals  of  dilTerent  lengths,  which  are  filled  by  internodal  growth. 
Tho  nodal  joints  aro  not  only  longer  than  the  internodal  ones,  but  also 
wider,  and,  as  a  rule,  increase  in  length  downward.  Their  diameter  i^ 
greatest  in  the  upper  part  of  tho  steni,  where  in  .some  species  of  the  Came- 
rata  it  is  often  twice,  and  exceptionally  three  times,  that  of  the  internodal 
joints.  Tho  projecting  margins  aro  sometimes  knife-like,  the  edges  occa- 
sionally crenulated,  spinous,  or  nodose.  Tho  greater  amount  of  length 
wdiich  characterizes  these  joints,  however,  does  not  extend  to  their  full 
thickness,  but  is  more  or  less  restricted  to  the  projecting  margins,  the 
miildlo  part  at  both  ends  being  depressed,  so  as  to  enclose  wholly  or  in 
part  tho  adjacent  internodals. 

In  tho  growing  Crinoid,  tho  stem  constantly  increased  in  length  by  the 
production  of  new  joints,  introduced  either  directly  beneath  the  calyx,  or  at 
some  distance  from  it.  The  joints  which  aro  formed  at  the  proximal  end  of 
the  stem  gradually  developed  into  nodal  joints,  and  all  those  intervening 
conipri.se  the  internodal  joints.  Tho  nodal  joints  of  the  Inadunata  and 
Camerata,  and  also  of  many  of  the  later  and  recent  Crinoids.  were  intro- 
duced directly  beneath  the  basals  and  infrabasals  respectively,  so  that  the 
uppermost  joint  was  always  the  j'oungest  joint  of  the  stem.  But  in  the 
young  Comatula,  in  which  the  top  joint  sub.se(|uently  develops  into  a  centro- 
dor.sal,  in  the  recent  Mesozoic  Milkricriims,  and  probably  in  tho  recent  lihho- 


1 


40 


THE  CKIXOIDEA  CAMERATA  OF  NORTH  All  ERICA. 


crinm  and  Culamocn'iiiis,  and  in  all  Ichtliyocrinidae,  so  far  as  observed,  the 
new  nodal  joints  were  formed  beneath  the  top  joint,  and  the  latter  remained 
permanently  attached  to  the  calyx.  In  Ajuocrinus,  in  which  for  .some  dis- 
tance the  upper  end  of  the  stem  is  greatly  inflated,  and  the  proximal  joints 
extremely  long,  it  is  possible  that  the  nodal  joints  were  introduced  below 
the  inllatod  part,  for  there  appear  to  be  no  innnature  segments  between  the 
upper  joints. 

The  intcrnodal  joints,  as  stated,  are  placed  between  the  nodal  ones  ;  and 
the  spaces  whicii  they  occupy,  and  which  continually  increased  in  length  and 
widtli  ill  the  growing  Crinoid,  are  the  internodes. 

The  i.icrease  in  the  length  of  the  internodes  took  place  gradually  in  a 
downward  direction  —  as  may  be  seen  by  comparing  the  stem  of  a  3'oung 
specimen  with  that  of  an  older  one  —  and  ixtri  passu  with  the  formation  of 
new  joints  just  below  the  calyx.  Hence  in  the  upper  part  of  the  stem  there 
is  a  vaiiable  number  of  premature  internodes.  Those  nearest  the  calyx  are 
the  siiortest,  and  consist  of  the  smallest  number  of  joints ;  wiiile  the  inter- 
nodes in  tiie  lower  part  of  the  stem  all  contain  the  same  number  of  pieces, 
and  all  joints  have  approximately  the  same  proportions.  The  joints  of  the 
upper  part  vary  in  the  same  internode  from  a  growing  leaflet,  invisible  in  a 
side  view,  to  an  almost  fully  developed  joint ;  and  the  upper  internodes  fre- 
(juently  consist  of  single  pieces.  But  they  are  followed  more  or  loss  rapidlj' 
by  internodes  of  two,  three,  or  as  many  more  ossicles  as  it  required  to  com- 
plete the  maximum  number  of  the  species,  the  younger  joints  being  inserted 
ne.xt  to  tile  older  ones,  which  are  distinguished  by  their  greater  prominence. 
In  the  upper  part  of  the  stem,  the  joints  of  subsequent  growth  are  readily 
recognized,  in  some  •-pecies  more  .so  than  in  others ;  I^ut  toward  the  terminal 
end,  where  all  ossicles  attain  almost  nn  equal  size,  it  is  often  diflJicult.  The 
stem  matured  from  tlie  root  up,  and  remained  at  the  upper  end  permanently 
in  a  state  of  immaturity. 

The  maximum  number  of  internodal  joints  varies  con.siderably  among 
the  species.  There  may  be  only  one  or  two  to  the  internode  throughout 
the  stem,  or  many  more.  The  largest  number  observed  in  Paleozoic  Cri- 
noids  is  about  fourteen  ;  but  among  recent  Pentacrinida)  as  many  as  forty- 
flve  have  been  counted,  and  as  many  as  seventy  in  Mesozoic  species. 

The  internodes  of  some  species  begin  at  quite  a  distance  from  the  cal^-x, 
while  others  have  no  internodal  joints  at  all.  The  former  is  manifestly  the 
case  in  certain  genera  of  the  Ichthyocrinidaj,  in  which  the  upper  part  of  the 


MORPIIOLOGICAL  TART. 


41 


stem  is  enlarged  somewhat  as  in  Ajn'ocrmis,  except  that  the  joints  of  the  en- 
hirged  part  in  tlie  lehthyocrinidac  are  very  short,  and  increase  but  very 
shghtly  in  length  downward.  These  plates,  which  have  no  internodals  inter- 
posed, extend  to  the  full  length  of  the  inflated  part,  and  their  number  varies 
in  different  species  from  about  twenty  to  fifty,  but  is  constant,  or  nearly  so, 
in  the  same  species.  They  are  followed  distally  by  a  large  prominent 
joint,  from  which  the  internodes  begin.  The  latter  are  formed  in  the  usual 
way,  larger  and  smaller  joints  following  each  other  at  interv.als,  and  the 
nodal  joints  are  rather  prominent. 

The  stem  of  a  Platjcrinus  has  generally  no  internodes,  and  all  young  joints 
were  introduced  next  to  the  basals.  The  joints  are  elliptic,  and  the  apposed 
faces  of  the  joints  throughout  this  genus  are  provided  with  articular  ridges, 
which  follow  their  long  diameters.  A  similar  structure  occurs  in  the  recent 
Rhizocrimis  and  Balhi/ci-iims,  and  both  of  them  are  apparently  destitute  of 
internodals.  The  Silurian  Mursvpiocrimts,  however,  with  a  circular  stem, 
which  is  otherwise  most  closely  allied  to  Plati/crimis,  always  has  well  defined 
internodes  ;  and  this  forms  perhaps  the  best  distinction  between  the  two 
genera. 

The  absence  of  internodals  is  not  confined  to  specimens  with  elliptic 
stems,  or  to  those  with  articular  ridges.  They  are  wanting  also  in  Mespi- 
locrimis  with  a  round  stem,  and  in  which  the  joints  rapidly  attain  a  length  of 
from  three  to  four  times  their  diameter  (Plate  II.,  Fig.  3).  In  Ehodocrinus 
there  is,  so  far  as  observed,  but  a  single  ossicle  to  each  internode,  and 
througliout  the  stem  a  larger  plate  alternates  with  a  smaller  one. 

In  a  few  Palreozoic  Crinoids,  the  whole  stem  is  divided  longitudinally,  its 
joints  being  either  quinque-  or  tri-partite.  The  former  is  the  case  in  Ohio- 
cn'nits,  Edenocrimis,  Barifcrbms,  Ammalocrimis,  and  probably  others ;  while  a 
tri-partite  st-^m  has  been  observed  only  in  Ilctcroerimis.  The  stem  segments 
alternate  with  the  proximal  plates  of  the  calyx ;  i.  c,  they  are  interradial 
in  dicyclic,  and  radial  in  monocylic  Crinoids. 

Most  Crinoids  are  provided  with  cirri,  which  are  given  off  from  the  nodal 
joints  at  intervals,  cither  throughout  the  whole  length  of  the  stem,  or  only  at 
its  distal  end.  The  former  is  more  generally  the  case  among  the  later  Cri- 
noids, while  in  the  majority  of  Palajozoio  forms  the  cirri  are  restricted  to  the 
lower  part.  In  Neocrinoids  they  are  more  regidarly  distributed,  and  occur 
in  whorls ;  in  Palneocrinoids  they  are  generally  arranged  singly,  and  at  irregu- 
lar intervals.     The  Pentacrinida3  have  five  cirri  to  each  nodal  joint,  which 


42 


THE   CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


are  invariably  radial  in  position ;  or  tliree  cirri  from  one  node,  and  two 
from  the  adjoining  ones,  so  arranged  that  the  cirri  of  two  joints  corre- 
spond in  position  to  the  five  of  the  one  joint.  The  size  of  the  cirri  varies 
among  species,  some  being  ninch  stouter  than  others  and  also  longer ;  but  as 
a  rule,  they  increase  somewhat  in  length  downward,  and  taper  to  the  end. 
They  move  rapidly,  according  to  A.  Agassiz,*  quicker  than  the  arms,  and  are 
used  "  as  hooks  to  catch  hold  of  neighboring  objects,  and  on  account  of  their 
sharp  extremities  are  well  adapted  to  retain  their  hold." 

The  functions  of  the  cirri  in  Palaeozoic  Crinoids  were  probably  more 
limited  than  in  recent  ones,  for  in  most  of  them  any  rapid  movement 
would  be  incompatible  with  the  structure.  This  is  especially  the  case 
with  those  of  the  Camerata,  and  it  may  be  a  question  whether  these 
appendnges  should  not  receive  a  different  appellation. 

The  cirri  of  the  Camerata,  except  perhaps  those  of  certain  species  of 
Dichocrimis,  are  mere  branches  of  the  stem,  and  were  obviously  capable  of 
very  little  motion.  They  occur  only  in  the  lower  part  of  the  stem,  and  in 
many  cases  were  probably  restricted  to  the  root.  They  rest  within  sockets, 
formed  at  the  sides  of  the  stem  by  a  truncation  or  excavation  of  one  or  more 
stem  joints.  In  riali/crimis,  in  which  we  have  observed  the  complete  stem 
more  frequently  than  in  any  other  genus,  they  generally  occupy  from  one- 
fourth  to  one-third  of  its  length,  and,  being  given  off  invariably  from  the 
longer  diameter  of  the  stem,  they  follow  its  twist.  In  some  of  the  species, 
each  successive  joint  is  cirrus-bearing,  either  at  both  sides  of  the  stem  or  one 
side  alternately.  In  others,  the  cirri  are  given  off  at  irregular  intervals,  and 
vary  considerably  in  length  and  width.  Throughout  this  genus  they  are  at- 
tached to  one  stem-joint  only,  which,  when  the  base  of  the  cirrus  is  larger 
than  the  usual  length  of  the  joint,  is  lengthened  on  that  side  to  accommo- 
date it.  The  radicular  cirri  are  larger  than  the  others,  and  are  generally 
provided  with  numerous  small  branchlets.  The  distal  end  of  the  stem  also 
terminates  in  a  sharp  point. 

In  stems  with  internodal  joints,  the  cirri  do  not  rest  alone  against  the 
nodals,  but  the  adjoining  internodals  share  in  the  formation  of  the  cirrus 
sockets.  In  some  species  the  sockets  involve  only  the  adjacent  joint  above 
and  below  ;  in  others,  two  or  three  of  them ;  but  the  cirrus  canal  invariably 
communicates  with  the  axial  canal  of  the  stem  through  the  nodal  joint.    The 

•  Ijptter  No.  3,  on  the  Dredging  Operations  of  the  U.  8.  Coast  Survey  steamer  Blake,  from  December, 
1878,  to  March  10, 1879.    Bull.  Mus.  Comp.  Zool,  Vol.  V.,  p.  296. 


[ 


J 


I 


^.w  .«-•-»«•  • 


MORPHOLOGICAL  I'ART. 


43 


t^ 


cirri,  although  they  may  be  arranged  singly  at  wide  intervals,  are  located 
radially  in  dicyclic  Crinoids,  and  interradially  in  monocyclic  ones.  This  is 
readily  perceived  on  pentangular  stems,  in  which  the  cirri  rest  within  the 
retreating  angles  of  the  joints,  so  as  to  alternate  with  the  salient  angles,  and 
hence  are  in  lino  with  the  salient  angles  of  the  axial  canal. 

Tlie  length  of  the  cirri  among  Camerate  Crinoids  was  very  variable,  and 
they  were  in  some  species  quite  formidable.  Wo  have  in  oar  collection  a 
fragment  from  the  lower  part  of  the  stem,  apparently  of  Batocriiius  graiulis 
(Plate  I.,  Fig.  2),  measuring  11  cm.  in  length,  and  tapering  from  a  diameter 
of  10  mm.  at  one  end  to  7  mm.  at  the  other.  It  gives  off  numerous  cirri,  of 
which  those  of  the  thicker  or  upper  end  are  but  little  thinner  than  those  of 
the  lower.  Three  of  the  lower  cirri  are  preserved  to  a  length  of  10,  15J,and 
15  cm.  respectively,  and  may  have  been  much  longer,  as  they  taper  but 
little,  still  having  at  their  ends  a  thickness  of  2i  to  3  mm.  Five  other  cirri 
are  broken  at  a  length  of  from  11  to  37  mm.,  and  eight  consist  of  only  two 
to  five  joints  ;  while  the  sockets  of  three  others  are  empty.  The  sockets  are 
deeply  excavated,  and  extend  to  nine  joints,  the  surface  being  radiated.  The 
distal  faces  of  the  joints  are  slightly  concave,  the  proximal  joints  shorter  than 
the  distal,  and  the  central  perforation  is  round  and  of  moderate  size.  Two 
of  the  cirri  in  this  specimen  have  a  remarkable  cyst  of  14  to  18  mm.  in 
length  by  9  mm.  greatest  width,  one  forming  the  distal  end  of  the  longest 
cirrus,  the  other  commencing  about  8  mm.  from  the  stem.  The  two  thickest 
joints  in  the  inflated  part  of  the  one  are  nearly  4  mm.  long,  while  the  length 
of  the  joints  above  and  below  the  inflation  does  not  exceed  \\  mm.  Similar 
cysts  are  frequently  found  along  the  stem,  but  have  not  before  been  ob- 
served to  occur  on  the  cirri.  They  resemble  the  Myzostoma  cysts,  which 
occur  along  the  arms  of  recent  Comatulae,  and  like  them  were  evidently 
caused  by  parasites. 

Ill  another  stem  fragment  from  the  Upper  Ilelderberg  of  Louisville,  Ky., 
every  joint  is  cirrus-bearing,  and  most  of  them  have  five  large  cirri  —  some 
four  or  three  —  which  almost  touch  those  above  and  below.  The  cirri  are 
preserved  to  a  length  of  35  to  40  ram.,  and  were  probably  much  longer 
(Plate  I.,  Fig.  3). 

The  cirri  of  the  ActinocrinidoB  generally  extend  to  one  third  the  height  of 
the  stem.  They  vary  greatly  in  size,  and  are  arranged  at  rather  wide  inter- 
vals. The  same  structure  probably  prevailed  in  the  IchthyocrinidaB,  at  least 
in  Onychocrinus  and  Taxocriims ;  while  in  the  Calyptocrinida3  cirri  occur  only 


44 


THE  CKINOIDEA  CAMERATA  OF  NORTH  A5IER1C.V. 


at  the  distal  enJ,  where  they  form  a  large  root  with  hundreds  of  small,  very 
delicate  branchlets. 

In  Dtchocrinus  the  distribution  and  length  of  the  cirri  are  extremely  vari- 
able. In  some  specii-'s  they  only  occur  at  the  lower  part  of  the  stem,  where 
they  are  short  and  arranged  far  apart.  In  others  they  continue  up  to  near 
the  caly.x,  and  are  quite  long.  The  former  is  the  case  in  D.  inornatus,  in 
which  they  are  singly  arranged,  and  rather  slender.  In  D.  pamiliis  and 
D.  iMimlus,  however,  they  follow  the  whole  length  of  the  stem,  and  are 
arranged  in  sets  of  two  or  more,  Avhich  are  so  long  that  the  tips  of  the  upper 
ones  reach  up  to  the  arms.  But  the  most  remarkable  cirri  occur  in  the 
Carboniferous  Ccaiip/ocriims  mijcloductylus  (Plate  LXXV.  Figs.  1  and  2)  and 
C.  citrij'er  (Plate  LXXVI.  Figs.  13  a,  b,  c),  in  which  they  begin  at  a  short 
distance  from  the  calyx.  The  stem,  as  usually  found  in  these  species,  is 
coiled  around  the  crown;  the  joints  are  circular  at  the  top,  but  gradually 
become  crescent-shaped,  the  concave  side  of  the  crescent  directed  to  the 
inner  side  of  the  coil,  and  both  its  horns  giving  off  extremely  long  cirri  from 
alternate  sides.  Very  similar  cirri  occur  in  the  Fistulate  genus  Ilequ'tocnnus, 
from  the  Silurian  of  Europe. 

Gli/ptocriiiiis  apparently  had  no  cirri  at  all,  not  even  at  the  distal  end, 
and  the  stem  was  probably  attached  like  that  of  the  Comatula3  in  their 
larval  state  by  means  of  a  dorso-central,  i.  e.,  the  enlarged  terminal  plate. 
RhoJucnnus  nanus  and  li.  Kirbi/i  have  a  few  scattered  cirri  at  the  lower  end, 
singly  arranged. 

The  cirri  of  the  Inadunata,  so  far  as  observed,  are  not  only  more  slender, 
but  were  apparently  more  flexible  than  those  of  the  Camerata,  and  they 
pass  up  more  frequently  to  the  top  of  the  stem.  The  latter  is  often  the  case 
among  the  Poteriocrinidac,  especially  in  SeupMocnmis  and  Graphwcrinus,  in 
which  the  nodal  joints  have  variously  from  one  to  five  rather  delicate  cirri. 
That  these  appendages  were  highly  flexible  is  shown  by  the  fact  that  they 
bend  in  all  directions,  —  some  being  straight,  others  curling,  some  directed 
upward,  others  downward,  —  a  feature  very  different  from  that  shown  in  the 
Platycrinidas,  Actinocrinidae,  and  Brtocrinidoe. 

Bckmnoo'imis  Jlorifcr  has  very  long  and  slender  interradially  disposed 
cirri,  which  extend  to  the  full  length  of  the  stem.  It  has  three  or  four  from 
each  nodal  joint,  the  upper  ones  directed  upwards,  and  extending  to  half  the 
height  of  the  arms.  B.  tifpus,  on  the  contrary,  has  no  cirri  to  a  length  of 
13^  cm.,  and  the  stem  is  circular  instead  of  stellate. 


I 


''f^ 


pnw 


MORPHOLOGICAL  TART, 


45 


I 


In  the  Cyathocrinidoo  the  structure  at  the  lower  part  of  the  stem  is  only 
known  in  Jiaiycrimis.  In  Ci/ulhocrinus  we  have  exatuined  the  stem  to  a 
length  of  10  cm.,  and  in  Pumocrimis  to  about  18  cm.,  without  finding'  any 
traces  of  lateral  cirri.  Neither  have  these  been  observed,  so  far  as  we  know, 
among  the  Anomalocrinidaa  or  Hybocrinidiu ;  but  in  JIumocrinus  scopurlm 
they  occur  at  the  lower  half  of  the  stem. 

The  stem  of  Duri/crimis  is  quinque-partite,  and  enlarges  gradually  to  the 
root,  where  its  diameter  in  extreme  cases  reaches  from  30  to  40  mm.  The 
root  consists  of  five  main  rami,  which  branch  into  smaller  ones,  so  located 
that  the  longitudinal  sutures  of  the  stem  bisect  the  rootlets,  and  the  large 
central  canal,  which  is  sharply  pentangular  in  the  stem,  becomes  elliptic  or 
linear  within  the  branches ;  the  latter  is  also  the  case  in  Ancijrocriniis,  of 
which  we  shall  speak  presently. 

The  axial  canal  is  central,  and  extends  to  the  full  length  of  the  stem, 
giving  ofi'  branches  to  the  cirri.  The  main  canal  is  circular,  angular,  or  pen- 
talobate ;  that  of  the  branches  sometimes  elliptic,  the  long  diameter  vertical. 
If  pentangular,  the  angles  are  directed  radially  in  dicyclic  Crinoids,  and 
interradially  in  monocyclic,  thus  alternating  with  the  projecting  angles  of 
the  stem  joints.  To  this  rule,  however,  there  are  two  exceptions,  and,  so  far 
as  we  know,  only  two.  In  Pcntacrimts,  and  the  monocyclic  Gli/ptocrbim  Forn- 
shelli  S.  A.  Miller,  the  axial  canal  has  the  same  orientation  as  the  outer  angles 
of  the  stem.  This  is  very  remarkable,  and  we  shall  consider  it  further  in 
discussing  the  basals  and  infrabasals.  The  canal  in  some  species  is  quite 
minute,  in  others  very  wide ;  while  in  still  others  the  central  canal  is  sur- 
rounded by  three,  four,  or  five  peripheral  canals,  as  in  the  case  of  Cuprcsso- 
criiiiis,  in  which  pentamerous  symmetry  in  the  stem  is  the  exception. 

In  recent  Crinoids  the  innermost  part  of  the  central  canal  is  the  internal 
vascular  axis,  and  consists  of  five  peripheral  vessels  arranged  around  a  cen- 
tral one.  The  former  are  downward  extensions  from  the  chambers  of  the 
quinquelocular  organ  at  the  base  of  the  calyx,  which  are  connected  with  the 
axial  vessel  of  the  chambered  organ.  Whether  such  vessels  also  existed 
in  the  stem  of  Palaaozoic  Crinoids,  of  course  cannot  be  ascertained  from 
the  fossil ;  but  that  a  quinquelocular  organ,  with  upward  extensions  to 
the  arms,  was  present  in  some  of  them,  is  indicated  by  the  structure  of 
Eupachifcrinus,  Catilloerinns,  and  Agasskocrinm,  where  the  inner  floor  of  the 
basals  and  radials  is  apparently  perforated.     Carpenter  *  thinks  it  probable 

•  Journal  of  Anatomy  and  Physiology,  Vol.  XIL,  p.  44. 


?l 


% 


46 


THE  CRIXOIDEA  CAMERATA   OF  NORTH  AMERICA. 


^;! 


that  tlic  peripheral  canals  of  Ciijircssocrintis,  which  consist  variously  of  three, 
four,  or  live  separate  passages,  correspond  to  the  peripheral  vessels  of  Pmla- 
criinis,  Jk/iisocriiius,  and  other  recent  Crinoids.  He  directed  attention  to  the 
fact  that  there  is  among  different  individuals  of  the  same  species  considerable 
variation  in  the  if<olation  of  these  vessels.  In  some  species,  in  which  the 
canals  appear  to  be  continuous,  there  is  but  one  large  tri-  or  tetra-partite 
perforation  at  the  base  of  the  calyx  and  throughout  the  stem,  which  he 
thinks  enclosed  the  four,  five,  or  six  separate  vessels  of  other  specimens. 
This  may  be  so,  although  we  cannot  quite  understand  how  the  three  or  four 
peripheral  canals,  where  they  exist,  can  be  extensions  of  a  quinquelocular 
organ. 

Tlie  variation  in  the  size  of  the  axial  canal  among  Palncozoic  Crinoids  is 
most  remarkable.  In  Plalycrinus  the  canal  is  sometimes  no  larger  than  the 
point  of  a  needle  ;  while  in  Barycrinus,  Cvfalocniius,  Eitallocriiius,  Alegistocrimis, 
Pmcc/iocriiiKs,  etc.,  it  is  often  from  one  half  to  even  three  fourtlis  the  width 
of  the  joints,  and  is  either  round  or  pentangular.  In  some  of  them  the  walls 
within  appear  as  if  built  np  of  thin  lamina)  with  spaces  between,  sometimes 
pectinated  and  variously  sculptured,  producing  a  great  multiplication  of 
exposed  surfaces.  In  Bari/crinus,  with  a  quinque-partite  stem,  and  a  sharply 
stellate  canal,  of  which  the  projecting  angles  are  directed  radially  toward 
the  suture  lines,  the  trigonal  inward  extensions  of  the  canal  are  pierced 
by  one  or  more  rather  large  pores,  which  pass  through  the  body  of  the 
plates,  so  as  to  enter  the  outer  faces  of  the  stem,  as  shown  on  Plate  I. 
Figs.  G  and  8  a,  h.  Five  other  series  of  pores  follow  the  longitudinal  suture 
lines,  and  these  also  communicate  with  the  central  canal. 

In  the  CrotalocrinidoB  and  Periechocrinites,  in  which  the  central  cavity  is 
proportionally  still  larger  than  in  Biiri/cniius,  the  inner  structure  appears  to 
liave  been  less  complex  ;  but  its  extreme  size  in  both  groups,  compared  witli 
that  of  other  Crinoids,  and  especially  with  recent  ones,  seems  to  imply  that  it 
was  not  a  mere  axial  canal,  but  performed  additional  functions. 

We  have  in  our  collection  the  root  of  a  large  Bai'^cnmis  (Plate  I. 
Fig.  7),  which  must  have  been  attached  to  a  smooth,  solid  substance,  for 
the  lower  surface  of  the  root  is  perfectly  flat.  In  this  root  only  two  of  the 
five  primary  branches  were  developed,  and  these  are  but  partly  preserved, 
but  enough  is  seen  to  show  that  they  had  been  placed  on  a  level  with  the 
truncated  lower  face  of  the  main  trunk.  The  development  of  the  other 
three  cirri  seems  to  have  been  checked  by  contact  with  the  bottom,  but  their 


'^    —mi 


'v>«K,v.sSiarw«K  igwr-* 


JIORPIIOLOGICAL  PART. 


47 


outlines  arc  faintly  indicated  along  tlio  edges  of  tlie  specimen.  Tlie  middle 
part  of  the  truncated  lower  face  is  perfectly  flat,  and  there  are  no  traces 
sliown  of  an  axial  canal.  But  in  an  outward  direction  we  find  grouped 
around  a  closed  centre  numerous  small  canals  comiecting  with  the  interior. 
These  canals  form  upon  the  surface  well  defined  ramifying  grooves,  which 
pass  out  to  the  periphery,  and  seem  to  communicate  with  the  surrounding 
water.  In  another  detached  root,  likewise  with  a  flat  bottom,  tiio  rami- 
fications at  the  distal  end  were  not  exposed  in  tiic  specimen,  but  wore 
opened  out  by  grinding.  The  specimen  has  two  root  trunks  of  eqiiiil  size, 
which  are  united  at  the  bottom  by  an  irregularly  formed  limestone  deposit, 
and  around  the  projecting  truncated  lower  end  there  are  a  numljer  of 
small  openings,  which  connect  with  the  canals  from  the  two  rootlets. 
Whether  the  cirri  of  all  Palncozoic  Crinoids  open  out  at  their  ends,  will 
perhaps  never  bo  satisfactorily  ascertained.  may  state,  however,  that 

the  finest  hair-like  branches  which  have  come  under  our  observation  are 
perforated  at  their  extremities. 

When  in  the  Revision  we  directed  attention  to  the  variations  in  the  size 
and  complexity  of  the  axial  canal  (Part  I.,  p.  15),  we  suggested  that  the 
column  was  probably  in  .some  cases,  and  perhaps  in  all  Pala;ozoic  Crinoids, 
subservient  to  respiration.  To  this  Dr.  P.  H.  Carpenter*  replied  that  he  did 
not  think  it  unlikely  that  the  pores  near  the  ba,se  of  the  column  may  have 
served  to  admit  water  into  the  stem,  and  thence  into  the  ca>lom  ;  but  he 
doubted  if  the  canals  opened  at  the  ends  of  the  rootlets,  concealed  as 
they  were  below  the  surface  of  the  ooze,  as  the  water  introduced  to  the 
stem  by  those  passages  could  not  have  been  very  useful  for  respiratory 
purposes.  Neumayrf  regarded  the  stem  of  the  Crinoids  a  greatly  modi- 
fied organ,  whose  original  form  could  only  be  explained  by  the  structure  of 
certain  Cy.^tids ;  and  ho  thought  it  was  primitively,  as  it  is  in  tint  group, 
a  sac-like  extension  of  the  calyx,  and  was  plated  in  a  similar  manner.  In 
corroboration  of  liis  views,  he  alludes  to  our  observation  that  in  Crinoids 
with  pentangular  stems  the  faces  and  angles  of  the  stem  occupy  a  definite 
position  to  the  proximal  ring  of  the  plates  in  the  calyx. 

Similar  views  were  expressed  by  A.  Agassiz.  t  He  says  :  "  Tiad  the  pen- 
tagonal stems  hold  a  definite  relation  to  the  calyx  has  been  clearly  shown 

•  Quart.  Joum.  of  Gcol.  Soc,  18S0,  pp.  555-557. 

t  Stiimme  ilci  Thicrniclics,  p.  430. 

X  Calamocriuus :  Mem.  Mus.  Comp.  Zool.,  Vol.  XVII.,  p.  63. 


if 


48 


THE  CKINOIDEA  CAMEKATA  OF  NOUTII  AMERICA. 


by  Wachsmuth  and  Springer,  anil  goes  far  to  prove  that  the  stem  must 
originally  have  had  a  liir  more  intimate  connection  with  the  calyx  than  its 
representatives  of  to-day  have  ;  and  the  fact  that  in  a  number  ol"  Palujoioic 
Criiioids  the  axial  canal  is  very  wide,  compared  with  that  of  recent  t3poH, 
seems  to  indicate  an  additional  function  t'»  that  pf  the  axial  canal,  which,  as 
Noumayr  suggests,  we  cannot  explain  fr^m  recent  representatives." 

The  apposed  faces  of  the  stem  joints,  with  a  lew  exceptions,  are  marked 
by  a  series  of  more  or  less  well  defined  angular  ridges  and  alternating  fur- 
rows, which  radiate  from  the  opening  of  the  central  canal  toward  the  dorsal 
margin  of  the  joints,  but  occasionally  are  restricted  to  their  marginal  por- 
tions. The  principal  ridges  alternate  with  smaller  ones,  which  do  not  extend 
as  far  inward  as  the  others,  and  all  ridges  of  one  joint  meet  corresponding 
furrows  of  the  apposed  joint,  which  gives  to  the  suture  its  serrated  outline. 
The  faces  of  the  joints  are  Hat,  or  slightly  curved,  the  nodal  ones  having 
sometimes  a  slight  crest  around  the  canal,  which  fits  into  a  corresponding 
depression  of  the  apposed  internodal.  Tins  indicates  that  the  motion  of  the 
stem  was  quite  limited,  and,  as  Carpenter  remarks,  "only  of  a  passive  char- 
acter, due  to  the  current  of  the  water,  etc.,  and  independent  of  the  will  of 
the  animal."  On  coming  in  contact  with  other  animals  it  was  capable  of 
bending  sideways,  and  of  returning  to  its  natural  position  when  the  obstruc- 
tion was  removed. 

In  Platycfinus  and  Bourgucticrinus,  in  which  the  faces  of  the  stem  joints 
are  elliptic,  their  surfaces  are  provided  with  a  well  defined  transverse  ridge 
following  the  long  diameter  of  the  joints,  with  fossae  at  both  sides,  and 
surrounded  by  a  marginal  reticulation.  The  ridges  follow  the  twist  of  the 
stem  downward,  admitting  motion  in  all  directions.  In  these  families  there 
seems  to  have  been  a  sort  of  rudimentary  articulation  between  the  suc- 
cessive joints,  while  in  the  other  families  there  was  only  a  loose  sutural 
union. 

As  to  the  habits  of  Crinoids,  very  little  is  yet  known,  even  of  the  recent 
ones.  We  know  that  in  their  pedunculate  state  the  Comatuloo  were  fixed 
by  means  of  a  large  plate,  the  so-called  dorso-central ;  and  this  led  to  the 
belief  that  all  Stalked  Crinoids  were  permanently  attached  in  a  somewhat 
amilar  manner.  But  this  has  never  been  satisfactorily  proved,  and,  as  we 
know  now,  is  not  always  the  case  with  the  recent  Pentacrinidac.  The  distal 
end  in  most  PaloDocrinoidea  tapers  rapidly  and  uniformly  to  a  point,  and  the 
terminal  branches  are  given  off  from  several  joints,  and  not  from  a  single 


\\ 


MOKrHOLO(JICAL  TAUT. 


49 


one,  except  in  a  very  few  cases.  In  the  Hudson  River  group  of  Cincin- 
nati we  occiwioniiUy  liiid  crinoiiliil  disltH,  attaclied  to  pieces  of  coral,  which 
closely  resemble  the  dorso-ceiitral  of  Antcdun.  These  disks  have  a  pit  or 
depression  at  the  middle  of  the  upper  face,  sometimes  enclosing  a  small 
stem  joint.  They  are  irregularly  round,  and  some  of  them  have  small  pro- 
cesses passing  outward  from  the  sides,  which  seem  to  represent  primitive 
cirri  (I'late  1.  Figs.  9,  10),  It  is  now  worthy  of  note,  that  we  find  in 
the  same  bods  somr  remarkable  crinoidal  stems,  with  their  lower  ends  wound 
around  some  stem  fragment  or  other  object,  almost  as  neatly  as  thread 
upon  a  spool,  the  column  gradually  tapering  ns  it  coils,  and  becoming  very 
small  at  the  end.*  It  has  always  seemed  to  ns  that  these  stems  and  the 
terminal  plates  belonged  togt-ther,  and  were  separated  during  the  life  of  the 
Crinoid.  Detached  roots  are  found  in  considerable  numbers  at  Burlington 
and  Waldron,  and  in  almost  ever^  case  the  root  parted  from  the  stem  a  little 
ab'^ve  the  radicular  cirri;  but  it  it:  curious  that  hardly  ever  are  parts  of 
the  crown  found  associated  with  them.  From  these  facts  we  may  infer  that 
the  stem,  at  least  in  some  cases,  became  iletached  from  the  root,  so  that  the 
Crinoid  could  change  its  place  of  attachmont.  A  detachment  of  this  kind 
actually  took  place  in  a  large  number,  if  not  in  all,  recent  PentacrinidoB,  as 
.shown  by  Sir  Wyville  Thomson,t  P.  11.  Carpcntf,  and  others.  The  former 
describes  this  structure  in  Piulaenmis  W//riUc-Thniiiy>iii  as  follows  :  "  All  the 
stems  of  mature  examides  of  this  species  end  inferiorly  in  a  nodal  jo'  it 
surrounded  by  its  whorls  of  cirri,  which  ciu've  downwards  into  a  kin',  of 
grappling  root.  The  lower  surface  of  the  terminal  joint  is  in  all  .smoothed 
and  rounded,  evidently  by  aI)sorption,  showing  that  the  animal  had  for  long 
been  free.  I  have  no  doubt  whatever  that  this  character  is  constant  in  the 
present  species,  and  tha<  the  animal  lives  loosely  rooted  m  the  soft  mud, 
and  can  change  its  place  at  pleasure  by  swimming  with  its  pinnated  arms; 
that  it  is,  in  fact,  intermediate  in  this  respect  between  the  free  genus 
Antcihn  and  the  permanently  fixed  Crinoids."  Carpenter  found  a  number 
of  other  species  o^  Poidtcrinii-",  and  some  of  Melacrimis,  in  the  same  condition. 
Roots  apparently  of  Pcn/acrinm,  and  belonging  to  mature  or  almost  mature 
specimens,  are  occasionally  found  on  telegraph  cables,  but  so  far  as  we  know, 
minus  the  crown  and  main  part  of  the  stem  ;  and  it  is  qnite  probable  that 
all  PentacrinidoB  were  able  to  detach  themselves  and  float  about. 

•  S.  A.  Miller :  Joiirii.  Cindn.  Snc.  Nat.  Hist.,  Vol  III.  Plate  7,  Fig.  34. 
t  The  Depths  of  the  Sea,  pp.  442-4 14. 

7 


CO 


TIIK  CmXOIDKA  CAMKUATA  OF   NOKTII   A.MKHKA. 


Ciii'pcnter  *  further  Htiitcs  that  in  Piiittwriiiiis  Wi/vllU-lhoiiiHon!  iha  x\oih\\ 
juint  Iruiii  wliieh  thu  Hcpiinition  takes  place  "  MOiiietiiiies  Iosen  its  ordinary 
chiiructcrs  altogether,  becoming  nuicli  enlarged  and  rounded  below  ho  an  to  be 
almost  heniisplierical  in  appearance."  And  in  a  t'ool-noto  lie  miys :  "  The  un- 
usual enlargement  of  the  nodal  joint  sug'jestH  the  idea  that  tlie  structures 
which  have  been  descrilted  by  Hall  under  the  name  Aiic'/rocniniK  i  may  be  the 
detached  stems  of  a  I'ahuocrinoid  in  the  semi-free  condition,"  —  in  which  we 
fully  agree  with  him.  Aiici/rncilni.i  has  the  form  of  an  anchor,  with  four  lidok- 
like  processes  aroimd  n  central  ascending  stem,  which  nt  its  distal  end  is 
provided  with  a  small,  rounded  tubercle,  closing  the  opening  of  the  central 
canal  exactly  as  in  some  cases  of  Piv/iimnnn.  That  this  stem  is  morphologi- 
cally in  the  same  condition  as  that  of  Pnilucriinn*,  nobody  will  deny  nfler 
examining  the  specimens.  The  four  lateral  extensions  were  doulitless  radi- 
cular cirri,  whose  joints  were  obliterated  by  calcareous  overgrowth,  as  in  the 
lower  part  of  its  tetramerous  stem. 

Something  similar  to  this  may  have  taken  place  in  other  Palicozoic  Cri- 
noids;  and  it  is  (|uite  pr()I)al)le  that  the  terminal  end,  as  it  appears  in  the 
specimens,  is  in  many  cases  not  homologous  with  the  part  by  which  the 
young  Crinoid  had  been  formerly  attached,  but  is  a  product  of  later  growth. 
We  suspect  this  to  be  the  case  in  the  Actinocrinidio.  Platycrinidtu,  and  other 
forms  in  which  the  terminal  part  tapers  rapidly  to  a  point,  and  cirri  are 
given  off  from  the  sides.  It  would  not  I;e  a  great  departure  from  the 
structure  of  the  Comatuhv,  if  we  bear  in  mind  that  their  centrodorsal  is 
a  modified  stem  joint,  bearing  cirri  upon  its  outer  surface.  The  only 
essential  difference  would  be  that  in  the  Pala^ocrinoid  the  stem  separated 
at  its  Imnr  end,  anil  in  the  Comatulao  at  the  tipper. 

That  the  young  PaUvocrinoid  in  its  early  life  was  attached  by  a  dor.so- 
central,  we  may  fairly  infer  from  what  we  know  of  the  dcveloinnent  of  the 
Comatuhe,  ami  from  pala?ontological  evidence.  The  indications,  however, 
leave  it  somewhat  douI)tful  if  the  fi.xation  was  permanent.  We  believe  that 
in  the  majority  of  cases  among  the  older  Crinoids  the  stem  was  afterwards 
separated  from  the  root,  and  that  the  animal  subseiiuently  led  n  free 
lift.  In  only  two  instances  do  we  know  that  Paheo/oic  Crinoids  were 
attached  by  what  appears  to  have  been  originally  a  dorso-central  plate :  in 

•  riinllciipor  Rep.  on  \]\c  Stalked  Crinoids,  p.  19,  nnd  fnot-nntc. 

t  Fil'lecnth  Ann.  llcj).,  X.  Y.  Si'ilc  Cab.  Niit.  Hist.,  1802,  pp.  89,  90. 


MOia'HoLOGK'AL   I'AIIT. 


61 


"  Chii'forriiiii.s  "  (litni.i*  nml  in  h'/ini/iz/i/nrnnitu  minxiix.j  Ixitli  (k'scril)iMl  liy 
II;ill.  Ill  tliu  roniicr  till-  pIiUo  jm  lixod  to  a  .Mtem  riiigmeiit,  and  clo^t'ly 
n'noiiil)lt-'!<  till)  i»liile  lijfiiiL'd  \)\  nn  on  I'liitu  I.  Fi^s.  [),  10,  liiiviiijr  likt-  tliiit 
Hiiiall  l)inl(liiig  cirri.  Tiie  /■JifcK////i/uriiiiii'<  \n  a  young  Hpociiiicn,  wliich  niiiy 
liave  iKM'isliL'd  ijul'oie  leaciiing  the  fioi'  stiigo,  Dclaelifd  roots  of  this  ><iiccic'H 
have  Im'cii  luiiiiil  in  hirgo  mniiljers,  even  hir^aT  onus  tliaii  tliat  rij,nirt'd  liy 
Hail.  Ill  some  localities  they  are  .so  aliiiiidant  that  they  lie  in  coiitaet  in  the 
roek  ;  but  tliey  nro  very  rarely  associated  with  i)iece.s  of  the  stem  proper,  or 
with  [larls  oC  the  crown.  These  roots  .seem  to  have  liei-ii  ilerived  Croiii  a 
central  disk  (dorso-centrul),  iVoiii  which  tlie  niiineroiis  hranehes  were  given 
olT  in  a  similar  manner  as  the  immntiire  cirri  IVom  the  terminal  plate  of 
''  Cliilnirn'iiitx  "  vidnis. 

Among  recent  (.'rinoids,  siicli  terminal  ])lutes  have  been  found  in  ronnec- 
tion  with  fragmentary  stems  in  V<il<iiii'iriliiiis  Dimiivi/cH  Agassiz.t  and  in  J'cii/n- 
triiina  unrcsliiinis  Carpenter,^  in  which  the  stein  increases  in  width  downward  ; 
but  it  is  uncertain  in  lioth  cases  whether  the  stem  is  fractured  or  hail  been 
cast  olT  by  the  animal.  DilVeieiit  is  the  striictuio  in  a  specimen  of  IUiImi. 
cnniis  ^{iwsiiiii,  ligured  by  Car[)eiiter.  ||  in  which  it  seems  as  if  the  dorso-central 
is  unrepresented.  There  arc  given  oil'  Irom  (he  sides  of  the  last  stem  joint  a 
few  irregular  cirri,  directed  downward,  and  tbe  distal  end  of  the  joint  is 
closed,  as  in  the  case  of  semi-free  Pentiicrinoids.  The  last  joint  dilTers  in  no 
other  way  from  tbe  joints  above,  and  has  the  same  form  and  length  as  the 
preceding  one. 

Among  Palivo/oic  Crinoids  wc  have  seen  tbe  complete  stern  in  upwards 
of  thirty  specimens  of  various  genera,  but  none  of  them  bad  a  dorso-contral. 
or  a  surface  for  attnehment ;  the  steins  invarialdy  terminate  in  a  point.  The 
terminal  portion,  however,  forms  no  part  of  the  primitive  stem,  but  is  of 
later  growth,  and  probably  served  the  same  purpose  as  tbe  lateral  cirri. 

Now  if  it  is  true  that  the  young  Crinoid  was  attached  b^'  a  dorso-central. 
as  we  may  suggest  from  the  ontogeny  and  pliylogeny  of  the  group,  then  all 
these  specimens  are  morphologically  in  alioiit  the  .«amo  condition  as  the  semi- 
free  Pentacrinidie,  and  not  essentially  different  from  that  of  the  free  floating 
ComatuliV.  This  interpretation  seems  far  more  reasonable  than  the  sup- 
position that  these  Crinoids  were  permanently  attached. 

•  New  York  Sintp  Cal).  Niit.  IlisI  ;  FilVonlli  Rep.,  Pliitp  I.  FIrs.  17  nnd  18. 
t  New  York  Stale  Miisnim  N»t.  llisl.;  Twi-nly-ciglith  Hop.,  I'liito  V,  Fi?.  .'>. 
i  Oil  Ciilainoct'ims;  M,m.  Jliis.  Coinp.  7,o<il.,  Vol.  XVII.  I'lato  28,  Figs,  i,  .i,  4. 
§  riiall.  Uc|..  oil  Sialk.  Ciiii. !  I'lale  XXX.  ii,  Fig.  I. 
II  Ibid.  I'laleLlII.  Fig.  7. 


!,' 


THE  CKINOIDEA  CAMKltATA   OV  NoKTIl   AMKIUCA. 


A  ponimiieiit  iixiitiuii  uf  tlio  C'liiiuids  would  i>urlmim  luHtrict  thu  geo- 
gi'iipliifiil  niiigo  of  tho  8j)ucii'.x,  wIiciviih  \vu  know  that  woiiiu  of  them  hiivo 
a  very  wide  range.  A  niiijority  of  tho  8pi'«'io."*  from  the  Lower  Rurlington 
group  lit  Hnrlington  are  I'oimd  iihnost  muiltered  in  tlie  Honthwi'sterii  part  of 
New  Mexico,  and  somo  in  Arizona,  and  nniny  Hpeeien  of  tiie  KeoUiik  group 
have  been  traced  from  southern  Iowa  um  far  down  an  Ahibama.  An(]  we  find 
in  Scotland  and  eastern  RuHsia,  with  but  flight  modification^,  tlic  same  form.<* 
wiiicii  fiourinhcd  in  tiie  MinHis-ipiii  Valley  during  the  epoch  of  the  Kaskaxkia 
gro\ip, 

B.     Bdsak  anil  Iiifrahttsals. 

Tho  bnso  of  a  Crinoid  consists  cither  of  one  or  two  rings  of  plates,  to 
which  the  terms  •'basals"  and  "  infrabasuls"  arc  applied.  In  dicyclic  forms, 
the  infrabasals  constitute  the  proxinial  ring  of  the  calyx  ;  the  basals  the  next 
circlet  above.  The  former  are  radially  disposed,  tho  latter  interradially. 
The  plates  of  either  ring  are  in  contact  laterally,  except  tho  basals  in  a  few 
species  of  Zi vcriiws  and  Culpiommis,  whore  tho  truncated  lower  angles  of  tho 
radials,  and  occasionally  tho  radianal,  reach  down  to  the  infraljasals.  The 
basals  are  followed  directly  by  tho  radials,  except  in  the  Acrocrinida>,  in 
which  they  are  separated  from  tho  latter  by  a  belt  of  auxiliary  pieces,  wljich 
occupy  a  large  part  of  tho  dorsal  cup. 

Tho  term  "  basals  "  was  applied  by  the  earlier  writers  invariably  to  the 
proximal  ring  of  tho  calyx,  and  when  there  were  two  rings,  the  plates  of  the 
jippcr  one  were  called  "subradials"  by  somo  authors,  while  others  called  them 
"  paniba.salia."  To  Dr.  P.  II.  Carpenter*  belongs  the  credit  of  having  been 
the  first  to  point  out  that  in  dic^-clic  Crinoids  tho  so-called  "subradials"  — 
and  not  the  proximal  ring  —  are  the  homolognes  of  the  basals  in  the  mono- 
cyclic base,  and  that  the  lower  ring  in  tho  dicyclic  forms  is  an  additional 
element  in  tho  calyx.  He  demonstrated  that  from  n  niorplmlogicnl  point  of 
view  the  same  set  of  plates  cannot  be  interradial  in  one  genus,  and  radial  in 
another,  and  he  considered  the  basals,  which  alternate  with  the  radials,  to  be 
the  representatives  of  the  genitals  in  the  Urchins.  The  force  of  his  argu- 
ment has  been  generally  ocknowlodged,  and  the  American  authors  writing 
since  187fl  have  adopted  Carpenter's  method,  with  the  exception  of  S.  A. 
Miller,  who  still  clings  tenaciously  to  the  old  terms.  Carpenter  called  tho 
plates  of  the  proximal  ring  "  under-basals,"  for  which  the  term  "  infrabasals" 

*  "  Ornl  and  Apical  Systems  of  Echiuoderma."  Quarterly  Journ.  of  Microscop.  Sci.,  Vol.  VTII., 
pp.  351-383. 


MOItnioUKilCAI,    I'AIIT. 


63 


ImH  boon  HiibHti tilted,  at  the  Hiigj^t-Mtion  of  I'lDr  Zittul.  But  Zittel,*  nnd  i\u> 
Ocriiiiiii  I'lilu'oiitoIogiHtM  giMicnilly,  wliilo  admittiiijj!  tlic  'lomology,  mid  ilic 
tiiiinu  "  iiit'iiilmsiiliii,"  iidoptoil  tlio  ti'tiii  "  |iiii'iibiiNaliii  "  fur  llii>  upper  ring  of 
pliitL'M  ill  lliu  diryclic  base,  cluiniing  tliiit  tho  word  "  biiwalH,"  if  iipplivd  to 
the  dicydic   liane  hk  wtdl,  inigiit  kad  to  coiiriisioii. 

Tbo  practice  of  giving  ditVorciit  natiicH  to  m'Im  of  plates  wbich  arc  nd- 
niittoil  to  bo  boiiiologoiis  was  jiisfly  criticisi'd  by  Carpi-iitor.t  and  nerioiis 
didiciiltius  arise  as  to  wiiicb  term  should  be  applied  in  certain  groups,  where 
infralmsais  exitit  in  some  species  and  are  wanting  in  others.  Such  a  case  is 
presented  by  tho  Apiocriiiidie,  among  which  de  lioriol  discovered  niilimeii- 
tJiry  infrabawils  in  two  Hpccics  of  MiKerkniiiin.  t  This  family  was  previously 
supposed  to  bo  monocyclic,  and  tbo  base  is  described  by  Zittel  as  consisting 
of  live  buxiilit,  whereas  in  the  two  species  above  mentioned,  the  live  corre- 
sponding plates  would  be  imrahasulx.  There  is  a  similar  case  among  the  I'eiita- 
crinidiu,  in  which  infrabasals  are  represented  in  one  genus,  —  Krlnivrhtvi'. 
Ill  the  Comatulic,  in  which,  according  to  Burj,§  small  infrabasals  occur  in 
the  ciliated  larva,  but  disappear  in  the  Peiitnf  rinoid  Htages,  the  very  same 
plates  would  bo  "  parabasa'.-i "  in  'be  ear'ier  stage,  and  basals  in  the  later. 
Carpenter  is  clearly  right  when  I"  says  ihat  this  terminology,  instead  of 
making  it  easier  to  students,  as  claimed  by  tho  Gerir.nii  Pala'ontologists, 
would  bo  the  source  of  endless  confiL-ion. 

A  different  interpretation  of  the  basal  plr^*!  ..as  given  by  Dr.  J.  Wnl- 
ther.ll  lie  accepts  Zittel's  terms  for  de.scripi.vo  pnrpose«,  hut  homologi/cs 
tho  infraba.sals  with  the  ba.sals  of  tb'  i's  nocyclica,  tho  >/arabasalia  "  with 
the  monocyclic  radials  ;  and  ho  tak  s  tin  radials  of  the  Dicyclica  to  repre- 
sent an  entirely  new  element  in  crinoid  morphology.  This  recall  Om  idea 
of  Lyon,**  who  took  the  basals  of  the  Blastoids  for  '•  primary  radials,"  and 
tho  forked  plates  for  "  secondary  radials."  As  Walther's  views  are  alto- 
getbor  out  of  keeping  with  the  facts  of  Palaeontology,  and  also,  as  we  now 
know,  with  those  of  tho  enibrjology  ol  recent  Crinoids,  any  further  discu.s- 
sion  of  the  subject  is  unnecessary. 

The  Comatulao  have  basals  only  in  their  earlier  stages ;  during  the  later 

•  Ilandbuch  d.  Pnlneoiitologip,  Vol.  I.,  p.  327. 

t  Aim.  mid  Mng,  of  Nat.  Hist.,  Julv  ISUO,  pp.  5-11 

I  I'lvleontuldRic  rrm.faio^    T  >nip  XI.,  I'art  I.,  pp.  ,').">3,  Bfi6. 

5  "The  Early  Stages  in  ''■  />r-,  iopiiioiit  of  Aiilcdoii  rosacea."  Report  of  the  Fifty-seventh  Meeting  of 
the  liiitish  Association  at  Mancni>.<r,  1887,  p.  73.5. 

II  Unlcrsnchnnjjen  iihcr  den  Ban  dir  Ciinoidccn,  Fnlaeontograpliica,  ISSfi,  Bd  XXXII.,  p  189. 
••  Geol.  Rep.  Kentucky,  Vol.  III.  p.  469. 


I'. 


54 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


period  of  Pentucrinoid  life  they  are  transformed  into  tlie  "  rosette,"  wliicli 
closes  the  upper  opening  of  the  centro-dorsal  cavity  lodging  the  cliandjcred 
organ.  The  Engeniaerinida)  have  no  hasals  in  the  adult,  and  Carpenter  sup- 
posed that  they  were  anchylosed  with  the  radials,  while  Zittel  and  Jaekel 
think  they  were  enveloped  by  exuberant  growth  of  the  radials. 

In  all  dicyclic  Crinoids  tiie  basals,  without  exception,  consist  of  five 
plates,  and  the  infrabasals  either  of  five,  three,  or  a  single  piece.  The  basals 
of  monocyclic  Crinoids  vary  in  number  from  one  plate  to  five. 

The  proximal  ring,  whether  con.sisting  of  one,  two,  three,  or  four  pieces, 
whether  ba.sal  or  infraba.sal,  is  divisible  into  five  elementary  plates  ;  and  the 
smaller  number,  where  it  exists,  is  produced,  as  we  shall  presently  show,  by 
anchylosis  of  two  or  more  of  the  primary  segments,  accompanied  hy  a  more 
or  less  complete  obliteration  of  the  suture  lines. 

The  earliest  dicyclic  Crinoids  had  five  i:ifrabasals,  and  the  first  mono- 
cyclic ones  ii\Q  basals.  Before  the  close  of  the  Ijower  Silurian,  there  ap- 
peared two  monocyclic  genera  with  four  basals,  both  having  a  special  anal 
plate  interposed  between  the  radials.  The  quadripartite  ba.se  reached  its 
culmination  in  the  Upper  Silurian,  and  disappeared  before  the  clo.se  of  the 
Devonian. 

Tlie  earliest  genera  with  a  tripartite  ba.se  occur  in  the  Upper  Silurian  ; 
some  of  them  have  an  anal  plate,  and  others  not.  When  that  plate  is 
represented,  tiie  basals  are  of  ecjual  size;  when  ab.sent,  two  of  the  basals 
arc  c<(ua].  and  the  third  about  half  smaller.  The  two  forms  continued  to 
exist  side  I)y  side  tc  the  end  of  the  St.  Louis  group  of  the  Carboniferous, 
when  both  became  extinct. 

The  bipartite  base  is  restricted  to  the  Carboniferous.  It  occurs  from  the 
Kinderhook  group  up  to  the  Coal  Measures,  but  is  found  only  among  genera 
with  a  large  anal  plate. 

It  is  evident  from  the.'io  observations  that  the  number  of  ba.sals  was  grad- 
ually reduced  in  Paheozoic  times,  and  that  in  ihc  Camerata  the  anal  phite 
was  introduced  after  the  quadripartite  base  had  made  its  appearance.  It  will 
now  be  .shown  that  this  diminution  of  number  was  the  result  of  fusion  of  two 
or  more  of  the  five  orijrinal  plate.s,  and  that  by  the  introduction  of  the  anal 
plate  tiie  I)ase  underwent  further  modifications.  The  manner  in  which  the 
modifications  in  the  number  of  ba.'^als  and  infrabasals  wore  efl'ected.  may  be 
best  understood  by  reference  to  the  diagrams  on  Table  A. 

Looking  at  these  diagrams,  the  transmutation  in  the  Camerata  from  five 


MOKPUOLOGICAL  I'AUT. 


55 


TABLE    A. 


IchthyotTinidsB. 

17 


U 


lehthyfMTinidie. 
18 


10 


16 


11 


IS 


Rhodocrinidie.  Thyaiinocriniilie.  Apiocrinidas  (young).  Apiocrinidre  (adult). 

DI.VOnAJrS    ILLUSTHATINO    THE    EVOLUTION    OF    THE    BASALS    AND    INFRABASALS. 

All  fisnros  rrprcsciit  the  anal  side  at  the  top;  «  =  posterior  basal j  d  and  « =  postcro-lateral  basals;  c  and  </=  anterior 
basiils  ;  /,  g,  h,  /',  /•  =  infrabasals. 


^1 


56 


THE  CUINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


baanls  to  a  less  miiiiber,  is  readily  iindeislood  among  genera  in  whiili  the 
anal  plate  is  wanting.  Wlien  the  ba.se  is  (inaihipaitite,  it  is  invariably  the 
two  anterior  plates  of  the  elementary  live  which  are  consolidated  (I'ig.  2). 
In  the  tripartite  base  tiiero  is  a  1'ii.sion  of  the  posterior  with  the  left  postero- 
lateral i)asal,  and  another  between  the  right  posterior  and  adjoining  antero- 
lateral-plate  (Fig.  3).  The  figure  shows  that  a  bisection  of  the  two  larger 
plates  will  reproduce  the  original  live  pieces,  interradially  dis]H).sed. 

The  case  is  nut  .so  simple  in  genera  with  an  anal  plate,  where  the  form 
of  the  basal  di.sk  is  changed  from  pentagonal  to  hexagonal  (Fig.  4).  ns  a 
bisection  of  the  larger  plates  woidd  produce  six  plates  instead  of  five.  This 
dilliculty,  however,  is  overcome  if  we  consider  that  the  introduction  of  the 
anal  plate  into  the  ring  of  radials  necessitated  corresponding  modifications 
among  the  basals,  as  othersvi-e  these  plates  wouM  lo.se  their  interradial  posi- 
tion. It  re([uired  either  the  introduction  of  a  basi-anal  (date,  or  an  increase 
in  the  si/e  of  the  original  pieces.  That  the  latter  occurred  among  the  Came- 
rata  is  clearly  shown  by  the  diagrams,  ami  the  evidence  leaves  no  doubt  at 
what  part  of  the  base  the  extra  width  was  in.serted. 

Taking  first  the  quadripartite  base,  and  comparing  Fig.  2  of  the  diagrams 
with  Fig.  8  —  one  pentangular  and  the  other  hcxangidar  —  we  fmd  that  in 
the  latter  the  posterior  basal  has  doul)led  in  size  (Fig.  7).  without  materi- 
ally changing  the  orientation  of  the  plates,  or  disturbing  their  general 
arrangement. 

In  tiie  tripartite  base  the  change  was  accomplished  in  a  diflerent  way. 
Tiicre  X  is  added  to  plate  c  (Figs.  !)  and  10),  and  the  plates  «//  and  c</  have 
coalesced,  and  hold  relatively  the  same  position  as  in  Fig.  3. 

Tlie  bipartite  base  is  protiably  derived  irom  the  tripartite  (Fig.  4),  which 
preceded  it  in  time,  and  x,  which  in  (he  latter  constituted  a  part  of  c,  is 
imited  with  cd,  and  ah  with  c  (Figs.  11  and  12). 

Now,  taking  up  Fig.  7,  and  eliminating  .r,  .«o  that  the  side  of  plate  u  rests 
against  the  plate  c,  we  obtain  Fig.  2,  and  by  a  similar  procedure  we  arc 
enabled  to  transform  Fig.  9  into  Fig.  ,{.  The  hexagonal  base  is  thus  re- 
stored to  its  primitive  pentagonal  form  without  disturbing  the  orientation 
of  any  plate,  cninpDund  or  simple. 

A  most  beautifid  confirmation  of  these  observations  is  furnished  by  an 
abnormal  specimen  of  Tcluocriitun  umhrosu-i  in  our  collection,  in  which  the 
regular  anal  plate  is  wiinting.  TilrincriiiUK  has  normally  throe  equal  basals, 
but  in  this  specimen  the  basal  plaii   to  the  left  of  the  anterior  ray  is  reduced 


MORPHOLOGICAL  TART. 


67 


to  one  half  its  normal  hIzc,  leaving  tlie  basal  disk  exactly  like  that  of  forms 
whicli  are  normally  without  the  anal  plate. 

It  is  very  remarkable  that  while  in  all  Crinoids  with  an  unequally  tri- 
partite, monocyclic  base,  the  smaller  plate  is  located  to  the  kfl  of  the  anterior 
radial,  this  plate  in  the  base  of  the  Bhistoids  lies  invariably  to  the  rii/lil 
(Fig.  G). 

Among  monocyclic  Tnadunata,  in  most  of  the  genera,  the  changes  among 
the  basals  are  not  so  readily  traced  as  in  the  Camerata,  owing  to  the  asym- 
metry of  the  radials,  which  more  or  less  aifected  the  form  of  the  basals. 
Most  of  them  have  five  basals,  but  there  are  some  genera  with  three  and 
four.  Anomalocriiiun,  .so  remarkable  for  its  asymmetry,  has  five  basals,  but 
there  is  frequently  a  small  additional  plate  interpo.sed  beneath  the  extremely 
large  left  posterior  radial.  As  this  plate  is  only  occasionally  represented, 
it  i.s  probably  not  of  much  morphological  importance.  S/orl/iiiiffocn'iiiis  and 
S>/i)iktlfiocn'ivi.s  have  three  unequal  basals,  arranged  like  those  of  the  Platy- 
crinida).  The  Calceocrinidno  have  three  or  four  basals  of  a  decidedly  irregu- 
lar arrangement.  Dchmiiocfinus-  is  the  only  known  monocyclic  genus  with 
five  basals  in  which  the  regular  anal  plate  is  represented ;  but  the  plate  is 
quite  narrow,  and  affects  but  .slightly  the  symmetry  of  the  plates  of  the 
proximal  ring.  In  the  FTybocrinidir,  a  large  radianal  is  interposed  between 
the  radials,  and  the  basals  consist  of  five  plates  of  a  rather  irregular  form. 

That  the  .smaller  number  of  basals  is  a  modification  of  the  original  five 
plates,  is  indirectly  shown  by  the  fact  that  in  many  species  o^  Plidi/cnims  the 
plates  are  so  closely  auchylosed  that  no  vestige  of  suture  lines  can  be  seen. 
In  some  of  them  the  lines  are  marked  by  grooves,  while  in  others  oven  the 
sutures  are  plainly  visible.  The  sutures  arc  always  better  defined  in  a 
young  specimen  than  in  the  adult,  and  in  some  species  can  be  seen  the  out- 
lines not  only  of  three,  but  of  five  plates.  It  is  further  significant  that  in 
all  ritit;/criid  of  the  Warsaw  and  St.  Louis  groups,  the  suture  lines  are  ele- 
vated, and  transformed  into  ridges  by  excessive  deposit  of  limestone  matter. 

The  case  of  Pisocrinus  is  very  interesting.  The  Silurian  speeies  plainly 
show  five  basals,  while  those  from  the  Devonian  of  the  Eifel,  which  have 
been  referred  by  Schultze  to  IVificriiim,  very  often  have  but  three.  A  care- 
ful examination  of  a  large  number  of  Eifel  specimens  leaves  not  the  least 
doubt  that  in  some  of  them  there  are  still  five  plates,  while  in  others  of  the 
same  species  the  number  is  reduced  by  anchylosis  to  three.  Among  recent 
Crinoids  also,  Carpenter  and  others  have  noticed  a  fusion  of  the  basals  in 

8 


If, 


^1 


58 


THE  CllINOIDEA  CAMEHATA  OF  NORTH   AMERICA. 


Ilyocriima  and  Rhizucnniis,  and  it  is  possible  that  tiie  former  ims  really  but  three 
basals ;  but  in  liluxocnnm  the  fusion  was  not  complete,  as  Count  Pourtales 
proved  by  inserting  a  needle  in  the  central  canal,  whereupon  the  base  sepa- 
rated into  live  pieces.* 

Tiie  foreyoing  facts  are  of  considerable  importance  as  to  classification. 
For  if  the  smaller  number  of  plates  is  merely  a  modilicution  of  the  originiil 
five,  the  number  of  basals  cannot  be  regarded  as  a  good  character  for  sepa- 
rating tiie  Crinoids  into  primary  groups,  as  was  practically  done  by  Angolin, 
and  afterwards  by  S.  A.  Miller. 

The  basals  of  dicyelic  Crinoids,  as  we  have  stated,  invariably  consist  of 
five  pieces,  but  their  form  differs  in  different  group.s.  In  the  Rhodocrinidio 
(Fig.  17)  they  are  all  heptagonal ;  while  in  the  Thysanocrinidte  the  posterior 
one  is  heptagonal,  and  the  four  others  hexagonal  (Fig.  IS)  —  the  former 
supporting  a  supplenientary  plate  at  each  intcrradin.s,  the  latter  at  the  anal 
side  oidy.  In  the  Fistulata,  all  five  plates  arc  hexagonal  when  there  is  no 
anal  plate,  as  in  the  Encrinidtc ;  but  in  the  Cyathocrinidiv,  whenever  that 
plate  is  represented,  four  of  the  basals  are  hexagonal,  and  the  fifth  hepta- 
gonal, precisely  as  in  the  Thysanocrinidic.  In  the  Poteriocrinidie.  and  all 
other  families  in  which  in  addition  to  the  regular  anal  plate  a  radianal  is 
represented,  oidy  three  of  the  basals  are  hexagonal,  and  the  posterior  and 
right  postero-lateral  basals  are  heptagonal  (Fig.s.  15  and  10). 

The  same  variations  occur  among  the  basals  of  the  IchthyocrInida\ 
Those  of  Ivhihi/iimiitis  agr'o  with  the  I>asals  of  the  Encrinidiv  ;  those  of 
Mis^ii/iicriiins,  TiiXdcriinifi,  For/ic.yiorrniia,  and  Culjiiocriiius,  with  the  i)lates  of  the 
Cyathocrinidiu;  while  the  basals  of  Lrriiiiiirriiiii><,  0' iioriiiincriiius  i\m\  tS'iii/niomiiits 
are  in  a  similar  condition  to  tho.se  of  the  Poteriocrinida\ 

Tineo  infraba.sils  have  been  oljserved  only  among  the  Fistulata  and 
Articulata.  They  are  represented  sparingly  among  the  former,  but  are  the 
rule  among  the  Tilithyocrinida;,  and  are  represented  in  the  larva  of  the 
Comatuhe.  Wherever  they  occur,  they  consist  of  two  large  plates  and  a 
smaller  one,  which  are  differently  arringed  in  the  various  groups.  In  the 
Fistulata,  according  to  Bather,  the  positiim  of  the  small  plate  is  not  constant; 
we  have  always  found  it  located  anteriorly  below  the  suture  between  the 
two  anterior  basals,  and  the  plates  /  and  ff  and  /  and  /,-  fused  together 
(Fig.  10).  In  the  Iclithyocrinida',  however,  the  small  plate  rests  below  the 
siiture  between  the  posterior  and  right  postero-lateral  ba.svl,  and/ and  y  and 

*  Jli'iiioirs  Mus.  Coinp.  Zool.,  Vol.  IV.,  p.  29. 


MORPHOLOGICAL  PART. 


60 


//  and  /,  respectively,  are  iinitetl  (Fig  13).  As  tiiis  Htrncture  is  apparently 
constant  in  the  latter  group,  we  regard  it  as  of  some  importance  as  regards 
classification. 

The  introduction  of  the  anal  plate  did  not  affect  the  Imsals  of  dicyclic 
CrinoidiS  in  the  same  numner  ns  in  the  monocyclic.  While  in  tlie  latter, 
when  the  plate  is  represented,  the  orientation  of  the  basals  is  slightly  dis- 
turbed, in  the  dicyclic  forms  it  remains  unaltered.  The  anal  plate  of  the 
latter  rests  invariably  upon  the  truncated  upper  face  of  the  posterior  basal 
(see  Figs.  11  to  18);  while  in  monocyclic  Crinoids  it  is  supported  by  the 
basals  a  and  e  (Figs.  10  and  12),  or  occasionally  by  a  and  .r  (Fig.  8). 

The  infral)asals  are  completely  anchylosed  in  the  Cupressocrinidiv,  fJas- 
terocomidiie,  and  in  S/riiiiiKiiovn'iiiis,  where  the}'  form  an  undivided  disk,  which 
Carpenter  and  others  have  regarded  as  representing  the  top  stem  joint,  as  in 
the  case  of  the  Apiocrinida)  and  Comatuliv.  At/iisKisocriiiiis,  in  its  pedun- 
culate younger  state,  had  five  well  defined  Infrabasals;  but  after  losing  its 
stem,  the  suture  lines  became  gradually  obliterated  by  limestone  deposit 
upon  the  surface.  The  .same  is  the  case  with  the  basals  of  the  monocyclic 
Eilri'icnims. 

Mr.  Bather  discriminates  between  Dicyclica,  P.cudomonocyclica,  and 
Monocyclica  vera.*  To  the  Pseudomonocyclica  he  refers  those  forms  in 
which  infrabasals  are  obsolete  in  the  adult,  but  were  represented  in  early  life. 
They  endjrace  most  of  the  Mesozoic  and  recent  Crinoids.  and  may  be  sub- 
divided into  two  classes  :  (1)  forms  in  which  the  infrabasals  gradually 
become  anchylosed  with  the  top  stem  joint,  and  (2)  those  in  which  they 
were  rcsorbed  in  the  adult.  In  the  former,  which  among  other  groups 
include  the  Apiocrinidoo  and  Comatula),  the  new  stem  joints  are  formed  below 
the  centro-dorsal  ;  while  in  the  latter,  which  are  typified  b^'  the  Pentacri- 
nida>,  the  top  stem  joint  is  the  youngest  joint  of  the  stem.  We  shall 
l)resently  show  that  both  these  forms,  although  the  infrabasals  may  have 
disappeared,  still  retain  the  characteristics  of  dicyclic  Crinoids. 

Several  years  ago  we  discovered  t  that  among  the  Pahi^ocrinoidea  there 
is  a  regular  alternation  in  the  arrangement  of  the  successive  parts  below  the 
radials,  and  that  the  orientation  of  the  stem  is  essentially  different  among 
monocyclic  and  dic3'clic  forms.  We  fotuid  that  the  salient  angles  of  the  stem 
itself,  and  the  projections  of  the  axial  canal,  are  reversed  in  the  two  groups, 

•  Ann.  and  Mnff.  of  Nut.  Ilisl.  (sixlli  scrips),  Vol.  V.,  April,  1890,  p.  310. 

t  Revision,  Part  III,  Section  I,  p.  7  (Proceed.  Pliila.  Aciid.,  Iss.'i,  p.  239),  with  ii  most  nnfortunntc 
transposition  of  terms,  wliicli  was  corrected  iu  the  appendix.    Also  18SS,  Proceed.  Pliilii.  Aend.  j).  351. 


60 


THE  CRINOIDEA  CAMEKATA  OF   NORTH  AMERICA. 


and  that  the  cirri,  wliich  in  dicyclic  Crinoidrt  ore  radial,  are  interrndinl  in  tlie 
otiiers.  By  employing  this  rule  wo  were  enabled,  in  many  caHes  whore  the 
infrabasals  are  hidden  beneath  the  culuiun,  to  determine  their  presence.  The 
law  of  alternate  arrangement  of  the  succes.sive  part3  i.s  shown  by  the  follow- 


ing table :  — 


Dic^cllc. 

Muiioc}'clic. 

1. 

Hasals. 

Interradial. 

Interradial. 

2 

Infrabasals. 

Radial. 

3. 

Column.    Exterior  angles  of. 

Interradial. 

Radial. 

Sections  of. 

Interradial. 

Radial. 

4. 

Column.    Sutures. 

Radial. 

Interradial. 

Sides. 

Radial. 

Interradial. 

Cirri,  wlicn  present. 

Radial. 

Interradial. 

Axial  canal. 

Radial. 

Interradial. 

This  law  is  only  applicable,  to  its  full  extent,  in  species  with  pentangular 
or  pentapartitc  stem  and  canal ;  but  we  infer,  from  analogy  of  these  forms, 
that  the  circular  stem,  wherever  it  occurs  in  dicyclic  Crinoids,  is  also  practi- 
cally interradial,  and  in  those  of  monocyclic  type  radial.  Our  observations 
were  founded  upon  Palaeozoic  Crinoids,  among  which  we  had  met  with  no 
exception ;  but  on  applying  them  to  Me.sozoic  and  later  Crinoids,  we  were 
surprised  to  find  that  in  most  of  the  so-called  monocyclic  forms  the  relative 
positions  of  the  column  and  cirri  were  reversed,  so  *hat  they  were  exactly  as 
in  dicyclic  Pala;ocriuoids.  Though  universally  con.sidered  to  be  monocyclic 
Crinoids,  they  were  built  on  a  dicyclic  plan  ;  and  this  led  us  to  inquire 
whether  all  those  forms  might  not  be  dicyclic,  whose  infrabasals  were  hidden, 
or  had  existed  in  their  larval  state. 

This  seemed  to  be  confirmed  by  another  observation  which  we  made 
among  certain  Paleozoic  forms.  In  some  genera,  notably  in  Gruphioctiiws, 
which  was  originally  described  as  monocyclic,  the  infrabasals  arc  so  extremely 
small  that  they  are  completely  covered  by  the  upper  stem  joint,  and  only  the 
basals  are  visible.  These  Crinoids  are  practically  in  the  same  condition  as 
Millciicrinus,  Apiocriims,  and  Pciiiacn'mts,  for  the  stem  occupies  the  same  posi- 


[ 


f 


MORPHOLOGICAL  PART. 


61 


[ 


tion  toward  the  proximal  ring  of  plates  visible  in  tlio  calyx  as  that  of  M'tllm- 
crlnits  and  Apiocriiiiis,  except  that  in  the  two  latter  the  .^pace  above  the  top 
stem  joint  is  vacant,  while  in  Gra/t/Hocriniin  it  is  filled  by  very  small  iiifViil)asals 
(compare  Fig.  17  with  Fig.  20  on  Table  A). 

Small  infrabasals  are  known  to  exist  in  the  base  of  the  Pentaciinoid  genus 
Extracriims,  and  de  Loriol  has  discovered  similar  plates  in  two  species  of 
Milkrurimts  (Plate  VI.  Figs.  1  a,  h,  and  2  <i,  I).  Those  of  M.  imhithiclijlitfi  he 
describes  as  follows:*  "Jo  distingue  tres  nettement,  sur  deux  iiidividus, 
cinq  piJjces  extrC'mement  petites,  Ti  peine  distinctes  jl  I'a'il  nil,  qui  sont 
logees  au  centre  de  I'article  basal,  chacune  reposant  sur  le  somniet  de  Tune 
des  carenes,  dans  une  direction  radiale,  au  centre  se  trouve,  ime  petite 
depression  qui  forme  le  fond  de  la  cavite.  Ces  petites  pieces,  que  je 
n'avais  jamais  encore  observees,  jouent  evidemment  le  role  de  ]iii"'c'os  infra- 
ba.sale-s,  mais  il  I'etat  tout  a  fait  rudimentaire."  Similar  pieces  wore  dis- 
covered by  him  in  his  M.  Orhiyiii/i,  of  which  lie  sa^-s  :  t  "  Kilos  no  pouvent 
nbsolument  se  voir  que  lorsque,  par  un  hasard  heureux,  I'article  basal  pent 
se  dogagcr  du  calice.  II  me  paratt  indubitable  que  se  sont  la  do  petites 
pieces  infrabasales  rudimentaires  semblal)les  jl  cellos  que  j'ai  signaloos  dans 
le  ]\[.  polydacli/his." 

Admitting  these  plates  to  be  infraba-sals,  it  is  certainly  quite  improbable 
that  other  species  of  Milkrierimis  having  a  pentangular  stem,  and  those  with 
a  round  stem,  and  the  species  o£  Ajiiocriiiiis, — a  genus  which,  according  to  de 
Loriol,  is  very  closely  allied  to  Mi/kricniiiis  and  GiuilnrdicriiiHs  —  should  hiive 
possessed  no  infrabasals.  In  all  species  of  ^lilkricrbius,  the  column,  unless 
it  is  round,  has  interradial  angles  (Plate  VI.  Figs.  1",  3,  4'',  5).  oxiictly  as  in 
M.  Orbigiii/i  and  all  dicyclic  Pahuocrinoids ;  and  hence,  if  the  genus  wore  not 
dicyclic,  this  structure  would  be  at  variance  with  that  of  other  (.'riudids.  AVe 
come  to  the  same  result  if  we  examine  the  vacant  space  witliin  tlie  basal 
ring.  Tliis  is  radial,  and  disproportionate  in  size  to  the  axial  canal  of  tlie 
stem,  which  is  small  and  circular  ;  whereas  if  it  represented  the  axial  canal 
of  a  monocyclic  Crinoid  it  should  be  interradial.  The  space  is  largo  enough 
to  have  contained,  besides  the  canal,  additional  plates,  which,  if  present, 
would  have  occupied  the  same  position  as  the  infrabasals  of  M.  Orhliini/i. 

The  column  of  dicyclic  Crinoids  abuts  either  entirely  against  tlie  infra- 
basals, or  partly  also  against  the  basals.     Tlie  latter  is  the  case  with  the  top 

•  Piilniiit.  Frnm.,  l^"  si'rif,  .Viiiinnux  Invprtt'bies,  Terr.  Jurassic,  Tome  XL  Premiere  Parlip,  Criuoidcs, 
Paris,  lS82-lS8i,  p.  553,  Plate  110.  Figs.  1  nml  2. 
t  Ibid.,  p.  5CG  (Plate  llfi,  Fig.  1,  A,  c,  </). 


I 


C2 


TIIK  CRINOIDEA  CAMKRATA   OK  NORTH   AMKRICA. 


Htt'iii  joint  of  Mi//<ricriiius  Or//ii/iii/i  imd  M.  pul^ihaii/lus ;  while  in  other  species 
of  tiie  Ai)iociini(lie  in  wiiieh  in('nibasiil.s  are  unrepresented,  tlie  eolinnn 
touches  the  biisals  only.  It  rests  against  the  onlcr  (dorsal)  surface  of  the 
plates,  whose  lun'cr  margins  are  bent  up,  so  as  to  form  an  inverted  pentan- 
gular concavity,  radially  disposed.  This  cavity,  which  is  occupied  and 
completely  fdled  by  the  top  stem  joint,  is  generally  grooved  nt  the  inter- 
basal  sutures,  and  produces  upon  the  upper  face  of  the  joint  five  angles, 
which  lit  into  the  grooves,  and  interlock  with  the  ba.sals  (Plate  VI.  Figs.  1 «, 
1 1>,  and  <}).  The  outer  edge  of  the  joint  at  the  uj)per  end  has  also  a  more  or 
less  radiid  outline  ;  while  its  lower  end  follows  the  orientation  of  the  stem, 
and  is  intornuliidly  disposed  when  that  is  pentangular. 

We  mention  these  particulars,  because  Carpenter,  in  criticising  our  gen- 
eralization,* umlertook  to  prove  by  the  angularities  at  the  upper  face  of  the 
stem  that  in  those  species  of  the  Apiocrinidso  in  which  the  stem  is  roimd, 
the  latter  was  radially  disposed,  and  not  interradially ;  and  that  those 
species,  according  to  our  own  rules,  were  monoc3clie  and  not  dicyclic.  lie 
overlooked  the  fact  that  the  top  joint  rests  against  the  turned  up  dorsal 
(outer)  siir/acc  of  the  basals,  and  not  against  their  inferior  fucfs.  The  surface 
to  which  the  "  centro-dorsal "  is  attached,  rei)resents  morphologically  the 
surface  of  the  concavity  for  the  reception  of  the  column  in  PaUvozoic  Cri- 
noids ;  the  inferior  faces  are  those  which  meet  the  infrabasals,  and  in  3f.  Or- 
hijiiyi  and  M.  iioli/daclylus  actually  supjiort  them,  but  in  most  of  the  Apio- 
crinidiv  they  enclose  a  vacant  .space.  If  this  space  was  filled  by  infrabasal.s, 
as  we  think  it  was  in  the  young  Crinoid,  the  columnar  concavity  and  the 
upper  face  of  the  stem  would  be  in  exactly  the  same  condition  as  in  the 
Ichthyocriuidie,  in  which  similar  angularities  occur  on  the  upper  face  of  the 
stem  1  Plate  II.  Fig.  4i).  The  uppei  face  of  the  column  in  all  Crinoids 
adapts  its  form  to  the  .shape  of  the  plates  to  which  it  is  attached,  and  if  their 
suture  lines  are  grooved,  it  will  be  correspondingly  ridged.  We  thus  believe 
that  Carpenter  misunderstood  the  structure,  and  that  he  overlooked  our 
statement  that  it  is  the  longitudinal  angles  ulonr/  the  column  which  alternate 
with  the  proximal  ring  of  plates  in  the  calyx,  and  not  the  angularities  or 
ridges  '/  /lie  upper  face. 

In  Itliiz'irriniis  the  condition  of  the  base  is  apparently  similar  to  that  of 
the  Apiocrinidie.      The  genus,  however,  was  described  by  Carpenter  t  as 


•  Ann.  nnil  ^rn7.  Xiit.  Hist  ,  'S\nnh,  ISSG,  p.  286. 
t  Cliall,  Ucp.  Stalk.  Crin.,  p   L>1G. 


MORPHOLOGICAL  PART. 


68 


monocyclic,  and  the  iippernioHt  stem  joint  an  tlie  lust  formed  pliite  of  tlio 
stenj.  But  he  seems  to  have  ehiinyed  liis  opinion  iifterwanlH,  for  in  ii  letter 
to  us,  dated  November  '28,  IS'JO,  he  writes  as  follows:  -I  have  spent  this 
morning  studying  my  material  ol'  Jt/iixocrimis,  including  some  fre.-h  spicinicn-' 
which  I  found  among  my  father's  collection,  and  1  conclude  that  you  an- 
right  in  considering  the  top-stem-joint  as  a  centro-dorsal  liUc  that  of  Jl'iiu- 
guflkrlum  and  the  Apiocriniihe.  It  is,  however,  always  the  smallest.  /.  <., 
thinnest  joint  of  tiie  stem.  Hut  it  is  distinctly  marked  into  five  fcissie  lor  the 
basals  by  radial  ridges,  and  this  is  sometimes  very  apparent  in  the  younger 
individuals.  See  Chidl.  Kep.  Plate  X.  Figs.  7  and  8.  It  is  more  maiki  d  in 
It.  Ifiiii'iioin  than  m  Ji. /o/o/riim.  The  pentagonal  space  in  the  centre.  I'late 
X.  Fig.  5,  is  nothing  hut  the  axial  canal."  He  tlien  continues;  ''  Ilif/ii/cniinx 
is  a  very  dilTerent  form,  with  its  very  numerous  thin  joints  at  the  top  of  the 
stem  (see  Plates  VII.  and  VIII '/),  and  I  have  been  thinking  for  some  time 
past  that  it  must  be  renmved  from  the  Uourgueticrinidiv  and  made  the  type 
of  a  now  family.  The  ten  arms,  and  the  trifa.^cial  articulation  are  idso  good 
characters,  as  the  latter  replaces  the  syzygies  of  lihizocriiiiiti." 

Except  in  one  point,  we  fidly  agree  with  this.  Kxamining  Plate  X  of 
the  Challenger  Report,  wc  fmd  in  Uhhocriiius  the  .space  within  the  l)a-id  ring 
very  diflerent  from  the  axial  canal  in  the  stem  joints  (see  our  Plate  \'I.  Figs. 
1(1,  /'),  the  former  being  fully  twice  as  large,  and  pentangular,  while  the  canal 
is  oval.  The  space  between  the  basals  is  radially  disjiosed.  as  in  the  Apiocri- 
nidii>,  and  we  believe  that  JiliLvurrhiiis  is  also  pscndonmnocyclic.  Its  structure 
is  altogether  different  from  that  of  Itidhi/rrlinii^  and  Il'incrlmis.  which  in  our 
opini(m  arc  true  monocyclic  forms.  They  have  no  centro-dorsal.  and  the 
nppi'rniost joint  is  the  last  formed  plate  of  the  stem.  The  open  spa<i'  within 
the  basal  ring  is  interradially  disposed,  and  lias  the  form  and  size  of  the 
stem  canal. 

Om- observations  on  the  Apiocrinidiw  led  ns  in  ISSG*  to  the  conclusion 
that  most  of  the  Neocrinoidoa  may  have  possessed  rudimentary  infral)asals  in 
their  larval  state.  This  rather  startling  statement  was  unfavoraldy  received 
by  Carpenter,  and  severely  criticised  by  him.t  lie  held  at  that  time  that 
with  the  exception  of  Eiirn'iiii»,  Kr/riwrinns.  }[iii-.viii!lc!<  and  Uiii/tirriiins,  all  Meso- 
zoic  and  recent  Crinoids  were  monoc\clic.  His  objections,  however,  did  not 
seem  to  ns  convincing,  and  in  Section  II.  Part  HI.  of  the  Revision,  pp.  294- 


•  division,  V.\H  III.,  Sc  .ioii  I..  |i|).  S,  71. 

t  Uibliogr.  Noticps.     Aim.  nnd  Mug.,  November,  ISsO,  p.  lOS. 


64 


TIIK   tKINOIDKA    CAMKUATA    OF    NOHTll    AMKKIt'A. 


209,  we  assertc'il  tliut  not  only  tlie  nmjority  of  Stalkid  CrinoidH,  but  uho  tlic 
Coumtiilii',  WLTo  built  upon  thu  tlicyolic  plan,  and  probably  liiid  intralnisals 
in  their  larval  statu. 

Tliu  centro-dorsal  at  tlio  Pcntaerinoid  stage  of  tlie  Conuitulo,  as  may  be 
seen  by  examining  IMato  VI.  Figs.  18  and  I'J,  agrees  cUwely  with  that  ol'lho 
Apiocrinidie.  It  is  intenadially  dispo.sed  at  the  proximal  face,  and  also  at 
the  distal  face,  so  that  its  angles  correspond  with  the  angles  of  the  baoals,  as 
in  those  ilicyelic  Crinoids  whose  infniba.sals  are  hidden  by  the  column;  and 
even  in  its  free  lloating  stage  the  eentro-dor.sal  retains  itH  interrailial 
position. 

So  strongly  were  wo  impressed  with  the  conviction  that  the  Comatula) 
arc  dicydic  Crinoids,  —  although  no  traces  of  infrabasals  liad  ever  been 
found  by  W^ville  Thomson,  the  two  Carpenters,  Goctto,  and  otiicrs  wlio  had 
exten-iively  studietl  the  embryology  of  Aiitidm,  —  that  we  urged  European 
investigators  to  nnd<e  fresh  search  for  these  plates. 

It  was  therefore  with  no  little  .satisfaction  that  we  learned  from  Dr. 
Carpenter  in  July,  1887,  that  infrabasals,  wlio.se  existence  we  had  predicated 
upon  paltDontological  evidence,  had  actually  been  found  by  Mr.  11.  Hiiry. 
This  important  discovery  was  announced  at  the  Manchester  meeting  of  the 
Briti.sh  Association,  and  communicated  by  Mr.  Bury  in  a  paper  on  "  The 
early  stages  in  the  Development  of  Aiitnlon  rosacea."*  The  jjlates  appear  in 
the  ciliated  larva,  and  consist  of  three  unecjual  pieces,  which  in  the  Pentn-" 
crinoid  stage  are  fused  together  with  the  top-stein-joint  (centro-dor.xal),  so  as 
to  form  together  with  the  latter  one  large  plate,  with  five  angles,  radial  in 
position.  One  of  the  plates  is  smaller,  and  has  but  one  salient  angle,  the  two 
larger  one-  having  two,  —  a  structure  which  suggests  that  the  two  latter  may 
represent  a  pair  of  ancliylosed  plates.  Three  similar  plates,  but  with  a  some- 
what different  orientation,  persist  throughout  life  in  the  Tchthyocrinida;,  but 
the  smaller  plate  of  Aiilnhm  rosacea,  if  we  understand  Mr.  Burj',  is  placed 
anteriorly  ;  while  that  of  the  IchthyocrinidoD  is  directed  posterioily  (Table 
A,  Figs.  14  and  15).t 

It  is  of  considerable  importance  that  the  infrabasals  of  all  Carboniferous 
Ichthyocrinidic  are  coalesced  with  the  top-stem-joint  (eentro-dor.sal)  similar 
to  those  oi  Aiilethn.  In  specimens  in  which  the  column  has  been  detached 
from  the  crown,  the  small  infraba.sals  generally  adhere  to  the  top-stem-joint 

•  I'liilosopliioal  Transnclions  of  llin  Itojal  Socioty  of  liOiidon,  ISSS,  pp.  257-.S0O. 
\  The  oriom.ilinii  nf  Ihis  plate  was  incorrectly  pivcn  liy  iis  in  llic  HcvisiDii,  Part  III.  Plate  0,  Fig.  23. 
Since  tlicii  we  liavc  fDund  out  tliat  it  is  located  in  nil  Iclilhyocrinidre  to  the  right  of  the  posterior  basal. 


MOUI'IIOLOUIC'AL   PART. 


C5 


(Pliito  II.  Fig.  4  /'),  being  in  hoiho  ciihom  porfoctly  fuNoil  wi(Ii  tliiit  plate  (Pinto 
VI.  Fig.  11).  Till'  coiulitioii  is  tlie  muiuo  uh  in  tliu  t\v<»  cpeeies  of  MI//1  liininm 
in  wliicli  iiifiui)iiNalH  liave  been  recognized,  and  we  coneiudo  from  analogy 
lliat  a  i'lision  of  llio>'o  platoH  eventually  took  place  in  ail  gioupH  in  wliicli  llio 
new  Btein  joints  nre  not  formed  directly  beneatli  llie  calyx. 

The  caHC  [»  dilTerent  among  the  Penlacrinidas  in  wbicb  the  now  Ktcm 
joints  constitute  the  iii)per  part  of  the  stem.  Of  the  principal  genera  wImlIi 
iiavo  been  referred  to  this  family,  one  —  Kitnurimin  —  has  small  infrabasuls 
persiHtent  through  life;  wliilo  in  the  other  two  —  Pritfiicn'niiii  and  MiKcrliiiia 
—  no  trace  of  them  can  be  found  in  the  adidt.  The  dicyolic  natun-  of 
Peii/acn'iiiiH  and  i^fiidcrinm  is  indicated  by  the  orientation  of  the  ftem  and 
cirri,  the  angles  of  the  stem  in  both  of  them  being  interradially  disposed, 
and  the  cirri  radially.  Hut  what  beeamo  of  their  infraljasals  ?  That  they 
fused  with  the  upprr  stem  joint,  like  those  of  the  Ichlhyocrinidiu,  need  not 
be  considered  in  this  family,  as  that  would  necessarily  prevent  the  formation 
of  now  joints  at  the  top.  They  may  have  been  resorbed  in  the  growing 
animal ;  but  it  appears  to  us  more  prol)al)le,  from  palieontologieal  evidence, 
that  the  plates  grailually  diminished  in  size,  and  finally  disappeared  allo- 
gethi-r  in  the  group.  The  structure  of  the  IVntacrinidic  is  very  difl'erent 
from  that  of  the  ComatuUo  and  Apiocrinida>,  and  it  appears  to  us  that  Cri- 
noids  in  which  the  upper  joint  of  the  .stem  is  the  youngest,  cannot  be  derived 
fi'om  those  in  which  the  top  of  the  stem  is  fused  with  the  infiaba.sals,  and  the 
two  groups  should  bo  widely  separated.  The  Apiocrinidic  and  Comatulro 
which  hive  a  centro-dorsal, —  /.  t'.,  in  which  the  iniVabasals  are  fused  with 
the  upper  stem  joint,  —  should  be  placed  together  with,  or  close  to,  the 
Ichthyocriniilie ;  while  the  Pentacriuidic,  which  in  many  points  agree  with 
the  structure  of  the  Potoriocrinida)  and  P^ncrinidie,  wo  think  might  be  safely 
referred  to  the  Inadunata  Fistulata. 

It  is  very  singular  that  while  in  E.t/riicn'inis  and  Milucruvis  the  projections 
of  the  open  space  within  the  basal  ring,  and  the  axial  canal  of  the  stem,  are 
radially  disposed  (Plate  VI.  Fig.  9),  both  are  decidedly  interradial  in  Piiita- 
criiiiis  (Plate  VI.  Fig.  8).  This  anomaly,  if  we  may  so  call  it,  was  regarded  by 
Carpenter  *  as  a  proof  that  our  generalization  upon  the  stem  is  not  applicable 
to  the  Neocrinoids.  This,  indeed,  seemed  at  first  to  bo  indicated  also  by  the 
orientation  of  the  stem  ;  but  Bury's  discovery  of  infrabasals  in  the  Comatula 
larva  changed  the  whole  aspect  of  the  case.     The  discovery  of  these  plates, 

*  Bibliogr.  Notices,  Auu.  and  Mng.  Nut.  llUt.,  March,  ISSC,  p.  2S7. 
9 


ee 


THK  CRIXOinEA   CAMKRATA  OF  NORTH   AMKRICA. 


wliOHO  preHoiico  we  had  inferred  from  (he  orientation  of  the  hirval  Htcni  nnd 
centro-dorHiiI,  xhowt'd  that  our  obnervntion  nawt  bo  one  of  wide  signifi- 
cance. The  aberrant  »triicture  of  the  canal  in  Pin/((criiiii.^  Hoen  not  invalidate 
tlio  law  an  we  have  found  it,  but  niniply  pointH  to  tlie  exiHtence  in  Hotne 
groups  of  transition  foriiis  iulerinediate  between  Mouocvdica  and  Dicyclica. 
Sueii  transition  forniH  inuHt  have  occurred  at  Honie  time  in  the  dcvelopinontnl 
luHtory  of  the  two  groups,  if  one  was  evolved  from  the  other.  Winch  form 
is  the  older  has  not  been  satisfactorily  proved,  but  the  evidence  of  Palo-ontol- 
ogy  points  to  the  Dicyclica  as  the  ancestral  type.  In  the  Canierata  the  evo- 
lution was  apparently  complete  at  nnd  ijcfore  the  Silurian,  but  it  is  probably 
still  going  on  in  some  of  the  later  groups.  In  the  Pentacriiiidie,  the  diminu- 
tive size  of  the  infrabasals  in  Ejlracrimta  may  be  the  first  step  toward  the 
monocyclic  base,  their  non-representation  in  Mcfucfimix  nnd  riHtacriiiiin  the 
next,  nnd  the  change  in  the  orientation  of  the  nxinl  cnnnl  another  important 
step  in  that  direction. 

We  have  discovered  a  case  almo.st  parallel  to  that  of  the  Pcntncrinidie  in 
the  Lower  Silurian  monocyclic  genus  (r/i//i/oeriiiiig,  which  has  a  radial  stem* 
and  an  interrndial  canal,  except  in  G.  Furux/ulli,  in  which  canal  and  stem 
both  are  radial  (Plate  XXI.  Fig.  5). 

Gl/z/i/ocriiiiis  belongs  to  a  series  of  monocyclic  nnd  dicyclic  Crinoids,  which 
are  so  closely  Intermingled  nnd  intinuitely  related  that  it  is  extremely  difficult 
to  separate  them  generically,  and  one  is  inclined  to  place  in  the  same  family 
monocyclic  and  dicyclic  forms.  There  is  perhaps  no  other  group  so  likely  to 
throw  light  upon  the  derivation  of  the  Monocyclicn.  The  base  of  G////ilocriiiiis 
has  been  variou.sly  described  as  consisting  of  one  or  two  rings  of  plates.  Ilall 
originally  defined  the  genus  ns  having  basals  only,  but  a  few  years  later 
thought  he  had  discovered  within  the  bnsnl  ring  in  some  of  the  species  indi- 
cations of  five  additional  pieces,  which  were  also  observed  by  Meek,  and 
called  by  him  "sub-basnls"  (Plate  VI,  Fig.  12).  S.  A.  Miller  described  the 
ba.se  as  consisting  of  but  one  ring  of  plates,  but  he  included  in  the  genus 
several  species  with  two  rings.  We  described  the  genus  as  dicyclic  in  Part 
II.  of  the  Revision,  but  in  Part  III.  placed  it  among  the  ilelocrinidaj,  after 
throwing  out  those  species  in  which  rudimentary  infrabasals  could  be  satis- 
factorily traced. 

•  The  nncleus  of  the  stem  in  0.  dtradtirlglHi  nnd  0.  T)i/eri  is  ol)scurpIy  prntnnptnlnr  at  the  uppor  end  ; 
the  projppling  edges  of  the  joints,  however,  give  it  n  circular  outline.  The  axial  canal  in  Iwth  species  is 
sharply  stellate. 


MOHIMIOLOdlCAI.  I'ART.  C,^ 

Thf  ciiHo  of  Ohji>ti>cnnm  Furnxhclli  is  very  rutimrkahlo.  Tlio  oiii'iiliilion 
of  the  nivxw  poiiitx  to  (i  iiioiiocyclic  biisu,  tint'  of  tliu  axial  ciiiial  It)  a  dioyclic. 
Bosidt'H,  tliL'  M|iocit'H  in  cIoHt-ly  ii-latoil  to  olluix  in  wliicli  tlio  raiuil  in  iiitt'i- 
radial,  and  tliu  Htuiii  radial.  It  \n  quite  evident  that  the  rule  whii-h  governs 
the  relatioiiH  of  the  partH  below  thu  bate  doeii  not  hold  ^ood  in  (i.  Fonix/n/ii, 
M  Wfl  And  it  in  thu  TohhII  Htatu  ;  but  \vu  think  thin  pidveM  nothing  more  than 
that  in  tiiiH  specieM  the  monocyclic  Ntago  waH  as  yet  incompletely  developeil. 
It  hIiouM  be  stated  that  while  the  aberrant  canal  of  ^'.  FiintshrlH  is  radial 
throughout  thu  whole  length  of  thu  Htem,  that  of  /'iii/umiiiin  \h  internidial 
only  ut  the  u[iper  portions;  it  toon  turua  to  circular,  and  wlieru  thu  cirru.i 
venwls  enter,  it  is  an  radially  disponed  a»  liiat  of  Mi/arriutm, 

Among  the  Ueteocrinidii',  also,  a  strictly  Silurian  family,  we  find  a  variety 
of  traiiMilion  forniM.  In  Kiiiovnnnii  the  H|)ecies  from  the  Trenton  group  have 
lurgu  infrabasals,  thonu  from  thu  IIudHon  liiver  group  tiuite  ruilimentary 
ones ;  while  in  Xcinimiiiix  and  T(iiiii»cfiiiH.i  the  infral)usnlM  are  altogether  un- 
r"pru«cnted.  Tho  axial  canal  of  Ilrlivcriims  U  radially  diipo.scd,  that  of 
Xmocrimia  and  TtimtucrlnuH  iuturradially.  The  three  forms  aro  very  closely 
related,  and  if  we  wore  to  separate  them  upon  the  structure  of  the  base,  it 
would  be  to  the  exclusion  of  other  characters  of  manifest  importance. 

The  examples  given  indicate  that  there  is  a  most  intimate  relation 
between  dicyclic  and  monocyclic  forms,  and  that  probably  the  latter  were 
deriveil  from  thu  Dicyclica  by  n  gradual  decrease  in  size  and  final  oiilitera- 
tion  of  tho  infrabasaU  in  geological  time. 

Blither  believes  with  us  that  dicyclic  Crinoids  preceded  the  monocyclic, 
but  he  states  that  so  far  as  tho  Fistulata  arc  concerned  he  has  found  nc  geo- 
logical evidence  to  prove  it,  at  lea.st  not  among  the  Fistulata.  lie  alludes  to 
the  llybocrinidso  as  being  probably  monocyclic,  but  he  rcgard.^  the  Iletero- 
crinida)  and  Anoinnlocrinidiu  as  true  Monocyclica.  As  to  Ili/hocrinm,  he  quotes 
the  earlier  part  of  thu  Revision,  in  which  we  stated  that  rudimentary  infra- 
basals  might  possibly  bo  present  in  the  genus.  This  supposition  is  not  veri- 
fied by  further  study  of  thu  specimens,  which  show  satisfactorily  that  no 
such  platus  are  represented.  Ilt/hocnnus  is  a  true  monocyclic  genus,  as  much 
so  as  Ile/erocniiiis  and  Anomahcrinus.  This,  however,  docs  not  exclude  the  idea 
that  all  three  forms  may  have  been  derived  from  the  Dicyclica,  and  there 
are  good  reasons  to  believe  that  it  Avas  so.  Tho  dicyclic  psendo-cystid  genus 
Purocrmis  is  so  intimately  related  with  Ilybocrinm  that  it  is  doubtful  if  the 
two  should  not  bo  placed  in  the  same  family.     Close  relations  also  exist 


H: 


68 


THE  CRINOIUEA  CAMERATA  OF  NORTH  AMERICA. 


betwcL'ii  Miroen'niis  and  locriniis,  and  between  OHaimcrinus  and  Ililvrocrinvs, — 
dicyclic  and  monocyclic  forms  respectively. 

While  tlie  evidence  thus  point-  Ic  the  probability  that  the  one  group  was 
derived  from  the  other,  it  is  dillicult  to  explain  the  change  in  the  orientation 
of  the  stem.  That  the  whole  crown  passed  through  a  revolution  of  3C°  is 
highly  improbable.  The  clinngo  probably  took  place  in  the  body  of  the 
stem,  modifying  its  form  to  suit  the  condition  of  the  ba.se.  The  stem  is 
round  in  most  of  the  earlier  Crinoids;  but  we  find  occasionally  within  the 
same  family  quadrangular  stems  from  a  quadripartite  base,  together  with 
pentangular  stems  from  a  quinquepartite  base,  whicli  goes  to  prove  that  the 
stem,  to  .some  extent  at  least,  adapted  its  Ibrm  to  the  conditions  of  the  base. 
In  a  similar  manner  intcrradial  stems  mr.y  have  changed  into  round  stems, 
and  these  into  radial  stems.  This,  however,  does  not  explain  the  change 
in  the  orientation  of  the  canal,  and  that  of  the  cirri.  The  latter  are 
directed  to  the  auglos  of  the  axial  canal,  through  which  they  communi- 
cate with  the  chambered  organ. 

The  only  writer,  besides  Bather,  who  has  discussed  the  derivation  of  the 
two  groups  i-<  Dr.  J.  Walther,*  who  takes  it  for  granted  that  the  simpler  — 
monocyclic  —  form  is  the  ancestral  one.  His  arguments  were  suggested  from 
his  study  of  the  pentacriuoid  larva  of  Autiihni,  and  are  extremely  hypo- 
thetical. They  are  based  upon  his  pecuuar  interpretation  of  the  basals  and 
infrabasals,  which,  as  he  now  will  himself  admit,  cannot  be  upheld  since  Bury 
discovered  infrabasals  in  the  larva  of  Antahn. 

C.     The  Radiak. 


The  term  '■  radials  "  is  applied  by  us  only  to  the  first  plate  of  each  ray. 
All  succeeding  plates  in  a  radi.-d  direction,  whether  free  or  incorporated  into 
the  calyx,  are  brachials.  The  name  was  given  by  Miiller  to  all  plates  up 
to,  and  including  the  first  axillary,  and  all  pieces  beyond  were  regarded  by 
him  as  armplates.  The  same  view  was  taken  by  Roemer,  de  Koninck,  and 
other  European  aiithors.  The  American  Palaeontologists  applied  the  term 
not  only  to  the  plates  of  the  first  order,  but  to  all  plates  of  the  rays  that  take 
part  in  the  cal3x.  Thoy  distingiii.shed  those  of  different  orders  as  primary, 
secondary,  and  tertiary  radial.s,  according  to  rank. 


199. 


•  "  Uutcrsucliungcn  iibcr  den  Bau  dcr  Crinoidccn."    PaliEontogrnphia,  180G,  Bd.  XXXII.,  pp.  180- 


IHOKPIIOLOGICAL  PART. 


60 


Miillcr's  interpretation  of  these  ])lates  was  somew  lat  modira'd  by 
Scliulize,*  wlio  assumed  that  tlic  arms  begin  invariably  witli  tlic  first  well- 
d( lined  iirticular  liicet.  lie  held  that  in  Ac/iiiocriiiits  and  Il/iiiilnciiiiiix,  whicli 
have  no  articidation  above  tlie  (first)  radials,  the  arms  commence  above  the 
first  axiUary;  but  that  in  Critioids  in  wliicli  the  rays  are  IVeo  above  tlie  first 
plate,  the  arms  begin  witii  tlie  second  plate  of  the  ray. 

Zittel,t  who  accepted  Schultze's  views  and  applied  them  to  the  later 
Crinoids,  describes  Enrnims,  Pciilncruins,  and  Mil/cricriims  with  one  radial 
followed  by  two  brachials ;  A/iiorriitiifi,  however,  with  three  radials.  He  evi- 
dently supposed  that  in  the  latter  the  first  articulation  occurred  on  the  axil- 
lary, which  is  not  the  case,  as  shown  by  Carpenter,  |  who  found  in  several 
species  of  that  genus  nt  the  upper  face  of  the  (first)  radial  a  transverse  ridge 
with  muscular  fossie  above  it.  A  similar  structure,  he  believes,  exists  in  all 
Apiocrinidii',  perhaps  with  the  exception  of  Oiivtfanlicn'niis,  which,  iicoording 
to  de  Loriol,  |  has  no  articular  facets  on  either  of  the  three  "  radials,"  nor 
even  on  the  distal  faces  of  the  axillary,  so  that  it,  cannot  be  determined  in 
this  genus  what  plate  of  the  ray  bears  the  first  facet.  This  shows  that 
Schult/e's  rule  does  not  readily  apply  in  this  group.  Still  more  serious  dilli- 
culties  arise  among  (he  Pahcocrinoidea.  In  most  of  the  Cainerata,  all  plates 
of  the  calyx  up  to  the  top  of  the  distichals,  and  often  much  higher,  are 
closely  and  immovably  united,  and  the  lowest  articulation  or  mobility  occurs 
at  the  base  of  the  arms. 

Applying  Schultze's  definition  to  the  Camerata,  it  is  quite  evident  that  all 
the  plates  of  the  dorsal  cup  in  a  radial  direction  had  to  be  called  radials, 
and  not  merely  tlmso  up  to  the  first  axillary.  This  we  did  in  our  earlier 
writings ;  and  instead  of  making  the  lower  facet  the  division  between 
radials  and  brachials,  we  took  the  calyx  for  the  boundary  line,  and  referred 
to  the  radials  all  plates  of  the  rays  which  take  part  in  the  calyx,  and  to 
tlio  brachials  the  plates  of  the  free  arms.  We  thus  recognized  among  the 
Camerata  an  indefinite  nutnber  of  radials,  while  their  number  was  reduced 
in  the  Inadunata  to  a  single  ring  of  plates,  a  course  which  was  afterwards 
adopted  by  S.  A.  Miller,  S.  II.  William.s,  and  Prof.  Worthen,  against  Hall, 
Meek,  and  others,  who  included  in  this  group  the  first  order  of  brachials. 

The  Ichthyocrinida^  in  which  the  lower  branches  of  the  rays  take  part 

•  "  Moiingrapliic  ilcr  Kctiiiiodcrnicn  di's  Killrr  Kiilkes,"  1S60,  Wicii,  pp.  5  uiul  9. 

+  lI.\ii(ll)uoli  (Ut  rnlirmilii1o<»ic,  Vol.  I.,  p.  X\9. 

t  Ann.  an    Muf;.  \at.  Ui>t.,  St.  C,  Vol.  VI.,  p.  12. 

§  "  Tiilec  utuluglu  Frau^-aisc,Jurassi(pic,"  Tumc  XL,  Tt.  I.,  p.  215. 


j 


'  I ; 


70 


THE  CKIXOIDKA   CAMKKATA  OF  NORTH  AMKKICA. 


ill  the  calyx,  wore  trcntod  by  lis  in  tlie  siiine  way  as  tlie  Camenita.  Scliiiltze, 
however,  described  'Ttuocn'iiiis  as  having  but  one  radial,  in  which  he  was 
correct  from  his  standpoint,  for  the  siicceedin;f  plates  seem  to  be  united 
among  themselves,  and  with  the  radials  by  loose  suture  or  a  sort  of  rndiinen- 
tary  articulation.  Carpenter  described  I'aihuriiuDi  and  the  Coinatiilaj,  which 
are  in  a  similar  condition  to  the  IchthyocrinidiJC,  as  having  three  radials  in 
all  cases,  whether  the  })lates  are  enclosed  by  perisome  or  not,  and  he  distin- 
guished the  rami  as  primary,  secondary,  ami  terti  ;vy  arms.  According  to 
him,  lUiisiicrliius  Jfiiiviniu,  with  ten  arms,  has  three  radials;  while  Ji.  h/oliiim, 
liive  Ciipirssocrliiiis,  Pmcniins,  and  all  Crinoids  with  but  five  arms,  have  one 
radial,  followed  by  brachials.  He  thus  made  the  second  plate  of  the  ray  a 
inrninl  rwliiil  in  the  former,  and  njirft  bfKchlal  in  the  latter,  giving  to  part.s 
which  are  undoubtedly  homologous  different  appellations,  while  distinct  parts 
were  thrown  together.  The  methods  of  treating  these  jdates  heretofore 
adopted  were  not  only  empirical,  but  inconsistent  with  the  principles  of 
morphology ;  and  the  want  of  luiiforinity  among  the  difierent  writers, 
respecting  the  terms,  must  have  been  perplexing  to  the  student  when  con- 
sulting their  works. 

In  1881,*  and  again  in  lS85,t  we  exprcs.sed  the  opinion  that  the  arms 
fundamentally  begin  with  the  second  plate  of  the  ray,  and  that  all  Crinoids 
have  but  one  ring  of  radials.  In  support  of  tiiis  we  stated  that  only  the 
lower  ring  could  be  homologized  with  the  oculars  of  other  Kcliinodernis  ;• 
that  in  the  simpler  form  —  tlie  Inadunalu  —  the  arms  were  free  from  the 
(first)  radials,  and  that  in  the  remaining  groups  the  lower  arm  plates  were 
incorporated  gradually  in  palacontological  time.  We  refrained,  however,  at 
that  time  from  changing  the  terminology,  finding  it  convenient  for  purposes 
of  description  to  continue  the  old  terms, 

Or.r  interpretation  of  the  plates  was  accepted  by  Caijienter  in  1884,]: 
who  confirmed  it  Ijy  the  developmental  history  of  the  plates.  The  "outer 
radials,"  he  says,  "  commenoe  as  imjierfect  rings,  which  soon  become  filled  up 
with  lengthening  fa.«ciculated  tissue,  just  ns  is  the  ca.se  with  the  stem  joints 
and  later  brachials ; "  but  "  the /;•»<  radials,  like  the  basals  and  orals,  com- 
mence as  expanded  cribiform  films."  TTe  further  alluded  to  the  f.ut  that  the 
.«o-called  primary  radials  of  Mcfacn'niis  are  pinnule-bearing,  —  a  thing  which 
wc  havo  observed  in  exceptional  cases  among  the  Poteriocrinidte  also. 


•  Rpvision,  I'nrt  IT.,  p.  10. 

I  Clialieiigcr  liop.  uu  the  Stalked  Crinoids,  p.  4S. 


t  Ilmi.Rirtlll.p.  12. 


MORPHOLOGICAL  PART. 


71 


Upon  commencing  the  present  work,  we  had  an  interchange  of  views 
with  Dr.  Carpenter  as  to  the  best  plan  to  be  pursued  respecting  these  plates, 
especially  as  to  whetlier  it  would  not  be  better  to  change  their  terms,  which 
we  considered  meaningless  from  a  morphological  point  of  view,  for  others 
more  appropriate.  We  proposed  to  restrict  the  term  "  radi;ds"  to  the  first 
ring  of  plates  of  the  rays,  and  apply  to  the  succeeding  ones  the  terms  "  pri- 
mary," "  secondary  "  and  "tertiary  brachials,"  according  to  their  rank,  in 
all  cases,  whether  the  plates  were  free  or  not.  lie  replied  that  he  appre- 
ciated the  great  advantages  of  the  proposed  nomenclature,  and  was  willing 
to  adopt  it  in  principle;  but  he  thought  the  terms  "primary,"  "secondary," 
and  "tertiary  brachials"  were  too  long  and  cumbrous,  and  he  proposed  in- 
stead of  them  the  terms  "  costals,"  "  distichals  "  and  "  palmars,"  respectivel\- ; 
which  we  finally  agreed  to  accept.  Carpenter  announced  our  agreement 
in  a  paper  "  On  certain  Points  in  the  Anatomical  Nomenclature  of 
Et'hinoderms."  * 

In  the  earlier  Inadunata  and  Articulata,  —  not  in  the  Camcrata  so  far  as 
observed,  —  the  radials  are  frequently  compound,  /.  c,  constructed  of  two 
segments  or  parts,  which  are  closely  united  b\'  a  hori/.oiital  suture,  and  in 
the  organization  of  the  Crinoid  count  as  one  plate.t  Among  the  Fistulata, 
compound  radials  are  found  in  the  Ileterocrinidaj,  Anomalocrinida%  Ilybocri- 
nida)  and  Dendrocrinida;.  In  some  of  these  families  tliey  are  restricted  to 
the  right  posterior  ray,  in  others  they  occur  also  in  other  raj'-s.  We  know  of 
no  case  in  which  the  compound  structure  extends  to  all  five  radials,  at  least 
two  of  the  plates  being  always  simple.  Among  the  IIeterocrinida>.  as  a  ride, 
the  right  posterior,  and  the  right  and  left  antero-lateral  radials,  are  compound, 
—  exceptionally  the  anterior  one  in  place  of  the  left  antero-lateral;  —  wliile 
Aiioimlocriiiits  and  Ohiocrinm  have  but  two,  and  loerimts,  Merocriiwn,  Ifi/Ztocniiiis 
and  Il'ipfocrmis  only  one.  It  is  further  worthy  of  note,  that  when  there  are 
several  compoun<l  radials,  the  corresponding  psirfs  are  of  nearly  equal  size; 
while  the  segments  vary  considerably  among  themselves  in  the  different 
genera.  In  JIf/crorriwi.i,  Ohiocriwis,  lorriinm,  Mcrocn'niis.  Ilf/hocniiim  and  Ihjlin- 
C'/stis,  the  lower  portion,  —  the  so-called  inferradials,  —  are  considerably 
larger  than  the  upper  or  superradials.  In  Aiwimilocriniis  and  Dciulrocrmis 
the  two  plates  are  of  nearly  equal  size;  while  in  Ecfr.inrn'iins  (TTc/irocriiiii/t) 
siiiiji/cx  the  upper  ones  are  three  or  four  times  as  large  as  the  lower.     In 

•  Aim.  .and  MnR.  Nat.  Hist.,  Spr.  fi,  Vol.  VI.,  pp.  11-18. 

f  \Vc  fiuvc  n  full  (loscriplic'i  of  tlirsc  pliitcs  ill  a  paper  "On  the  Pcrisoniic  PIbIcs,"  Pmcecd.  Arad.  Nat. 
Sci.  riiiln.,  October,  1890,  pp.  378  and  379. 


^1 


1 

ti 


72 


THE  CRIXOIDEA  CASIKRATA  OF  NORTH  AMERICA. 


Ammuhcnima  the  left  posterior  rniliiil,  wliicli  is  the  hiryest  phitc  in  the  calyx, 
is  sometimes  bisected  loiigitiuliniilly,  but  this  is  not  oonsttmt. 

The  gmdiiul  increase  in  size  of  the  upper  segments,  and  the  disnppcnrnnce 
of  compound  plates  in  other  rnys  than  tlic  posterior,  indirates  that  in  those 
Crinoids  tiiere  is  a  transition  from  three  compound  plates  to  one,  ami  also 
from  compound  to  simple  plates ;  and  we  think  it  may  be  safely  assumed 
that  there  was  a  time  in  the  early  history  of  the  Crinoids  when  the  arm- 
bearing  section  was  altogether  unrepresented.  This  was  apparently  the  case 
in  Bdnvcn'iiiis,  in  which  two  of  the  radial  plates  are  non-arm-bearing,  and  as 
these  plates  occur  in  the  same  rays  as  the  compounil  plates  of  AnoiiKil'icrijiiri, 
we  may  infer  that  Bitcrocrinun  is  the  ancestral  form,  lower  in  its  development 
than  either  AiioiiialiKrinitu,  IlnplocriiiHS  or  Licriiiiin. 

The  later  Fistulata  have  no  true  compound  radials ;  and  although  the 
lower  segment  of  the  posterior  radial  is  still  represented  in  many  of  them,  that 
plate  does  not  bear  the  same  relation  to  the  arm-bearing  plate  that  it  did  in 
the  earlier  forms,  but  a.ssumcs  the  functions  of  an  anal  plate.  As  such,  it  will 
be  considered  by  us  in  its  proper  place. 

Among  the  Larviformia,  true  compound  radials  occur  in  Ifn/ilocriiiiin,  which 
has  three  of  them  :  in  the  right  posterior,  and  the  right  and  left  antt'ro-lateral 
rays,  —  the  same  rays  in  which  they  occur  in  tlic  IIetcrocrinida\  The  com- 
pound plates  of  the  Ichthyocrinidaj  will  be  discussed  in  connection  with  the 
anal  plates. 

In  groups  in  which  the  radials  are  simple,  the  five  plates  are  approxi- 
mately of  the  same  size  ;  but  when  compound,  they  often  dificr  considerably 
in  size  and  form.  Tiiis  is  most  apparent  in  Calccocriiiiis,  CutillocrliwK,  Iln/ilvcii- 
iius,  and  I'l'^ovn'mis.  Among  the  Poteriocrinidie  also,  when  the  inferradial  is 
represented,  the  right  posterior  one  is  smaller  than  the  others,  and  of  some- 
what difl'erent  form.  In  some  Palacocrinoidea,  the  radials  are  separated  by 
supplementary  plates ;  while  in  all  later  Crinoids,  with  the  exception  of  the 
recent  genus  Tlummdlomnm,  thoy  are  in  contact  all  round.  In  the  Ithodocri- 
nidtc,  and  curiously  enough  in  T/iniiiiiK/ncriinis,  ih('y  alternate  witli  large  inter- 
radial  plates,  with  which  tliey  form  a  ring  often  pieces.  In  the  Thy.sanocrinida\ 
Actinocrinida>,  Batocrinida;,  Acrocrinidic,  Dichocrinida^  and  in  most  of  the 
Fistulata  and  Ichtliyocrinida;,  a  special  anal  plate  is  interposed  between  the 
two  posterior  radials.  In  the  Reteocrinidre,  they  are  separated  by  numerous 
small,  ill-defined  plates  at  the  four  regular  sides,  with  the  addition  of  an  anal 
plate  at  the  posterior  side.     In  the  Melocrinida;,  Eucalyptocrinida-,  Platycri- 


MORPHOLOGICAL   I'ART. 


73 


nicltr,  and    in  a  few  of  the   later  Fistiikta,  all    five  radiala  are  in  contact 
laterally. 

The  radials,  both  among  each  other  and  with  the  basal«,  are  united  by 
closo  Hiituri',  the  apposed  faces  being  generally  smooth,  but  occasionally 
wrinkled  or  striated. 


i 


D.     T/ic  Amis  and  Pinnulea. 

Admitting  that  the  arms  begin  with  the  first  plate  above  the  radials.  all 
plates  of  the  rays,  from  the  second  one  up,  are  brachials.  As  before  stated, 
we  adopt  the  terms  oostals,  distichals,  and  palmars,  for  the  first,  second,  and 
third  order  of  brachials,  respectively.  When  there  are  further  divisions  in 
the  rays,  the  plates  are  designated  as  postpalmars,  or,  when  greater  detail  is 
required,  as  brachials  of  the  fourth,  or  fifth,  order,  and  so  on.  We  also  dis- 
criminate between  fixed  and  free  brachials,  meaning  by  "  fixed "  that  the 
plates  so  designated  take  part  in  the  formation  of  the  calyx,  and  by  "  free  " 
that  they  do  not.* 

•  This  is  a  slifrlit  modilicaiion  (if  the  plan  proposed  by  Cnrpriitcr,  who  reserved  tlie  term  "/rrt-  hm- 
«■/}«//»"  lor  the  plates  of  the '.L-nniiialhraiichcs  aliiiif.  lie  also  dill'crcd  from  lis  in  oalliiii;  the  postpalmars, 
when  there  are  more  ihau  four  bifurcations  to  the  niy,  "  jiosljialmnn  of  the  lirst,  second,  or  third  order  " 


10 


KXIM.ANATION   OF  TAULK    B. 

TlIK    I'l.ATKS   OK   TlIK    KAVH   IN    DIKFKUKNT   (iKNKllA. 

1.     Pnrl  of  rav  ol' -'/((/•.v«/HorW;/H.< ;  iiisliils,  ilislicluils,  liibl  uiiil  secoiiil  imliniirs  —  (if  the  liitllT  only  those  of 

the  two  outer  sides  of  the  mys  — abiitliii),'  iigiiiiist  the  miliiiU. 
i      S,-aphiiirriim».     Anns  imiseriiil ;  |iiiiimlat<(l ;  (lii'holoiiiiziiiif;  tlic  joints  pinienlf. 
:t.     Ileli-mim-riiiiii  li/inn'.     Anns  \i.,i-<-iiai,  triviii^'  nil' armlets  at  inlervals, 
I.     A  lay  uf  IWiivioi-riiiMi  IVhilJiflili.     Arms  liiserial,  br.incliinB  ia  the  free  state. 
.-).     Troxiuuil  (lart  of  a  rav  of  Sl»)ii,ioi-n,iu.i  urii/ji/iin.     Arms  biseiial.  given  uir  alternately  I'riim  opposite  si.les 

(if  Inlnilar  appcnil:n,'es. 
fi.     l'rox:'i.(l  par;  of  a  riiy  of  Crntdlm-riiim  pulfher  t  Hiu  h'wer  l)raehial»  arran),'('il  »s  in   Fi|,'.    I. 

7.  I'art  (if  ray    -f  < hii/^'/ioc-hiiiM  niiiiii/om.     Arms  uiiiscrial ;  the  main  hrauehes  giving  olV  branehlets  in 

tlll^'  rs. 

8.  r..  !•  M'(rl.ou  of  rt  ray  of  Slmlo<;-i,iH«  recalls.     The  arms  given  off  from  the  proximal  plate  al  a'.Lcrnfttc 

mli^  «ilhin  the  calyx. 
•i.     Simhiitli:-    ''.IIS  U'lirhmniilhi.      Arm-    iiniserial,  eomposeil   exelusively   of  oostals ;  the   joints  nrrnngril 

aarulU  I 
'l\-  !  !;.  uiag  symlwls  arc  used  in  the  ligures  :   11  =.  radials  ;   I  =  primary  bmohials  or  eostals  ;   II  = 
seconchry  b,  ■■  -mI.  or  distlchals ;  III  =  lerlii.ry  brachials  or  palinars  ;  \\  ~  fourth  order  of  braehiids ;  V  ^ 
•'iuhordi-r    .'''-Mehials;  amission;  i>  =  |iiiniules ;  a.  =  armlets. 


MORPiior.o(;icAL  I'Aur, 


TABLE  U. 


76 


n 


' 


76 


TIIK   CHINOIDKA   CAMKKATA   OF   NUKTU    A.MKUICA. 


'I'lio  iibovo  terms  wliicli  wi'ie  acci'|iU'(l  \ty  Mr.  IJiitlicr  in  1890,*  ami  used 
in  liis  t'liilior  [lapLTs  -Om  tliu  Diilisli  Fossil  Ciinoiils,  were  in  Jiimiary,  IS'.t'J  t 
aliiiiiiliiiiL'd  l)y  liiiii  and  MubsUttitud  by  ullieis.  llu  .stated  tiiiit  ho  iuuiid 
cirtain  dilliculties  in  ilioir  applicatiuii  tu  I'ala'u/oiu  I'unus,  and  prupuMud  in 
plaoe  of  tlieni   liio  followinj^  terms  :  — 


I'l'iiiiibi'.ii'lis  =  uiir  iii'iiiiaiy  bracliiuls,  ur  CuiitalM. 

J''iist  piiuiiliiiii;!!      =     •'   first  co.stjil. 

"     SUCOIIll  CO.still. 

'•  axillary  cDstiil. 

•'  si'conilary  luiu'liials,  or  Disticlials. 

••  axillary  (ilsliclcil. 

••  tttrtiary  bricliialn,  or  Talniars. 

••  bracliials  ol'  tin'  I'ouitli  ordor   J 

•'  brachials  of  tin'  liltii  onlcr       >  rustpalmars. 

'•  brachials  ol'  the  sixth  order      ) 
Ktc. 


•Si'i'diid  laiinilirach 
rriniaxil 
Sii'iMidil)raohs 
Si'i'\iiidaxil 
Ti'rtiobrachs 
(jiiai'lihraidis 
Qiiiiilibr.\udis 
Si'Xtibrachs 
Etc. 


Tills  nomeneiatiiro  \n  based  upon  tlie  wnnio  principle  as  onr  own,  and 
even  tlic  names  are  not  so  very  dilTerent  eonsiilerinj^  that  the  terms  "cos- 
tals,  "  "  distielials,"  and  ••  palinais"  are  proposed  as  etpiivali-nts  ol"  ••  primary, 
seconilary,  and  tertiary  braeiiials;"  but  liatlier  propo.sed  tlie.so  terms  for  liie 
pinnuleless  forms  only,  and  broiiojit  out  anotlier  terminoloj,'y  to  be  applied  to 
pinnule-ixMirinj^  arms,  viz. :  — 


Munostidials  (First  Order). 

First  iiiDiiostidial. 

Scc()i\d  nionostirhal. 

^runaxil  (First  .Mainaxil). 
l>isliclials  (Second  ( Irder). 
Di.staxil  (.Seciiiid  Mainaxil). 


Tetra.stichals  (Third  Order). 

Ti'traxil  (Thinl  .Mainaxil). 

Uctastifhals  (F.mrlh  Order). 

(Fifth  (trder). 

(Sixth  <  >rder). 


Tiiat  tlio  l)raneirm<?  of  pinnulirorou.1  arms,  na  supposed  by  Hallicr.  is 
almost  quite  rej^uJar,  is  i)y  no  means  tbo  ease.  We  fre(|uenlly  find  among 
Camerate  Crinoids  rays  witli  three,  five,  six,  seven,  nine,  and  ten  arms, 
instead  of  two.  four,  or  ciiilit.  In  S/rotorriims,  there  are  lays  \vitl>.  tisirty 
arms  in  tiie  calyx,  and  tiie  "  Kinials,"  wiiicii  here  conii)iise  tlie  plates 
of  tiie  free  arms,  altliouj^li  j^iveii  ofl"  from  the  finirlciiilli  axillary,  are 
"Triacoutasticlials.'  .Still  inoie  complicated  is  the  case  in  i</'i/<iiitic'n)iiis, 
Eiiclnilii-ninix,  ni/iithicrliiuH,  and  Mi/ocriiiiiif,  in  which,  to  the  full  length  of  their 
rays,  from  the  costals  or  disticlials  up,  the  brachials  are  developed  into  rigid 

*  AiHi.  uiid  .Mag.  Vol.  V.  p.  313.  t  H'iJ-  Vul.  I.\.  |i|i.  .Jl-(il, 


MORI'll()H)(;iC'AL   I'AUT. 


cnlyciiie  tubcM,  and  tliu  original  piiimilos  into  iiltLMiiiitfly  aniingud  |iininile- 
bfiiring  arms.  This  hIiows  that  tlic  st-cond  imit  of  Uallu-r's  It'iiiiinology 
ciinnot  l)t'  citnit'd  out  pnietinilly,  and  we  sue  no  good  ix-aMtn  wiiy  thr  lornier 
turins  coidd  not  he  uxuil  tor  all  Ciinoids,  ]iinnnhilo  or  non-|iinnuiute. 

The  coslals  of  lh<;  C'unu'rala.  as  ii  rule,  consist  of  two  philcs  to  thi'  ray  ; 
I'xcoptioinilly  of  oiii'  or  threi-.  J'tiili/viiiiiin  has  <,'i'ni'raily  hnt  oni-  ;  hut  two 
of  its  oarliur  spocics  have  two,  ami  it  is  (piiti'  proltahie  that  tlie  genns  ori;:i- 
nally  had  two  costals,  which  later  on  were  united  into  one.  This  ^<eenls  to 
lie  conlirmed  hy  the  fact  tliut  some  of  the  species  liave  tiaiisverse  grooves  at 
the  dorsal  face  of  the  plates,  and  that  in  inultii)ra('hiale  species,  the  <lislichals 
and  succeeiling  onlers  are  composeil  of  two  pieces.  Slifnivriinis  al.^o  has  liut 
one  costal,  which  has  llu!  pro])ortions  of  the  '■ondiiued  first  and  second  plates 
of  /)ii/ii/ui n'liii.t,  with  which  it  has  very  dose  alliiiitii's.  'I'he  same  >iruclure  is 
found  in  Aii//irmt>iTiiiiis  and  llnilninliinK.  Diclutrrtinix  iuis  two  costal.s,  which 
form  a  sy/ygy,  the  epi/.ygal  supporting  an  arm.  The  allied  Tn/iininiini.s  ami 
J'/irn/nniiiiis,  however,  iiave  lint  one.  in  /ln/nrriiiiix.  iuu\  in  most  of  the  Hato- 
criniles.  the  fnst  costal  is  very  short,  aiul  is  frecpiciitly  anchylosed  with  the 
Hccoiid  in  one  or  moie  of  the  rays.  'I'hree  costals  occur  among  Camcrate 
Crinoids  only  in  /{i/nifiuiiis  Kl(ll(tri'<,  and  in  Hall's  imperfectly  known 
Hclilxiicriiiiix. 

Among  the  Articulata  the  nund)er  of  costals  is  more  variahio,  anil  ol'leii 
dilTers  among  the  rays  of  the  same  individind.     FnrhisiiinliiuK  A»/(i-^n:i*  may 
have  two  or  three  costals  in  all  its  rays,  or  lour  only  in  one  or  two  of  them 
Cii//ii"rriiiiis  and  Min/iilonuniis  have?  two,  Ichlliiiin'rlniis  anil    Tii.viiviiiins  two  tc 
tliree,  and  AiiiKorriiiim  hnt  one  ;  wliili!  Oiii/ilinrriiiiis  \m-i  from  three  to  six. 

The  numher  of  costals  is  still  more  varialile  in  certain  groups  of  the 
Fistiilata,  in  some  of  which  such  irregularity  is  the  rule.  This  is  the  case  in 
Ci/ii//i<>i-i-ini's  and  I'drisnrriiiiis,  in  which  one  ray  may  have  two.  the  adjoining 
one  three,  and  the  next  perhaps  five  or  six.  Cinlinrriiitin  has  two  to  three, 
A/ekn/iicriiiiis  from  two  to  .-^ix.    I^ess  variahle  among  the  rays,  hut  still  nuinor- 

•  UV  are  of  llir  (i|iiiii<iii  thai  For/zrai'iiriiniK  iiiihilh.  di'  KcmiiipkN  Ivpc  iif  tlii'  i;'""-.  i'  !.'"M(iiiiill,v  idiii- 
lic:il  Willi  Oiiyi-iorriiiMn  l.voii.  We  rid'iillv  (ilil.iincil  rioiii  'rMurnai,  lli'l|,'iuni,  n  llni'  s|HciiMc'ii  with  iiriiis, 
wliicli  I'lcarlv  slums  llial  il  lins  a  small  anal  liilir  iTstiiii;  iipnii  llw  fiisl  anal  \ihlr.  Tlie  r»\;\  arc  fivi-  aliovr 
ihr  llist  ('(Hliil,  and  aro  rxtrcnu'lv  licavv  Id  lln'  fonrlli  (li>liclial,  whrnco  llicy  hranoli  iiir  iiili)  minicidns  small, 
ciirvini;  arnlrls,  i\arll_v  as  in  (hiyrhorriiiiin  i:iyrii//i/ii^  I,vi>n.  Di'  Kcininck  slalcil  llial  in  liis  species  llic 
pliilcH  111"  the  anal  side,  wliieli  were  imperferllv  sliown  in  Hie  spi-einiens,  were  priilialilv  mure  nnmemus  llian 
lliDse  of  the  iillier  siili's,  wlierens  llie  fael  is  the  opposite  ;  ami  \U\-  slaleim  .1,  no  doidil.  led  Hall  and  others 
111  ri'lVr  /'./■*,■</;„•,■)//«»  Jfliisfhi  and  allied  forms,  in  whieh  that  aetnallv  is  the  ease,  to  de  Koiiiiiek's  Kenus. 
If,  therefine.  ile  Kmiinek's  type  is  that  of  Oiii/.-lim-riiin'.  the  latter  iianie  may  have  to  be  abandmu'd,  and 
B  new  Ki'iierii'  name  proposed  for  sncli  forms  as  /'.  .l//iiA.ii:i. 


^1 


I   r 


78 


THK  CHINOIDKA   CAMKllATA  OF   NOUTII    AMKUICA. 


Oil.",  ail'  tin'  CDstals  {){'  Dciii/rnrriiin.i  mid  llnmnvninis,  in  wliicli  wt'  liiive  roiin  I'd 
iiM  iiiiiiiy  a^<  M'Vi'U  ;  loirimia  lias  four,  Aii"m((t"cniiiix  IVoiii  two  lu  lour  in  flio 
Hunio  spt'fii'H.  Mont  of  tliu  otlior  Fi.-ttulatii  have  one  or  two.  Wlicii  there  is 
but  oiif  |)lali',  it  is  gi'iieially  twice  an  long  an  the  two,  tlie  hitter  fonuing 
a  H^z.vgy.  We  liiul  this  in  the  majority  of  the  I'oterioerinidii',  except  in 
the  iiiiteriiM'  ray,  which  in  some  species  has  as  many  as  twelve  costals.  while 
in  Dtiiers  it  lias  no  liiliircation  at  all,  ami  the  arm  is  eoiiiposeil  oi' costals  only. 
A  lew  of  their  species  have  Irom  five  to  eight  costals  in  each  ray,  anil  I'ulifi- 
ovrinm  iiimoiiriiiinix  from  ten  to  rourtecii.  In  the  Ilyliocriiiidie.  and  in  tin- 
Larviformia  ns  a  rule,  the  nnns  ure  formed  exclusively  of  costals  (Kig.  1); 
and  only  occasionally  in  .li/'ii/ivriims,  in  one  or  two  of  its  rays,  the  radials 
are  axillary  and  in  the  ahseiice  of  costals  support  two  rows  of  distichalH. 

From  these  facts  it  is  obvious  that  the  number  of  costals  does  not  consti- 
tute a  reliable  character  for  classification,  as  heretofore  HUpposed,  and  that  in 
some  groups  their  number  is  of  but  little  value  for  specific  distinction.  This 
is  oven  more  markedly  the  ease  with  rc-^ard  to  the  higher  divisions  of  the  rays. 

'I'lio  disticlials  are  borne  upon  the  axillary  costal,  which  splits  the  ray 
into  two  divisions,  and  all  succeeding  bifurcations  take  jtlace  from  one  or 
both  of  these  divisions.  To  this  rule,  however,  there  are  a  few  exceptions: 
Sfi't/aiiocriims  Kcitl/t/im,  a  few  species  of  Milncriiiiis,  I/i/nrnniis  and  Citlaiwivr'tuim, 
have  no  re'/ular  <listicliy,  and  all  their  branches  are  given  off  from  one 
trunk.  A  similar  structure  is  Ibiind  among  the  Poteriocrinidie  in  the  pos- 
terior ray.  In  most  of  their  species  with  two  arms  to  the  ray  the  jiosterior 
ray  has  but  one  trunk,  and  in  multibrachiato  forms  the  first  bifurcation  of 
the  posterior  ray  corresponds  with  the  second  in  tin-  other  rays,  nraiiching 
takes  place  either  alternately  from  opposite  sides,  or  by  means  of  dichotomy. 
The  former  is  very  froiueritly  the  case  among  the  Canierata.  and  is  the  rule 
in  the  Actiiiocrinidiu. 

The  arms  are  composed  of  one  or  two  rows  of  plates.  The  iiniserial 
nnns  arc  composed  of  either  rectangular  or  cuneate  plates,  the  former  being 
the  most  archaic  form.  The  cuneate  plates  arc  alternately  arranged,  and 
gradua  ly  pass  into  a  biserial  arrangement.  Arms  arc  called  '"  biserial " 
when  the  plates  interlock,  and  do  not  reach  to  the  full  width  of  the  arm. 
This  exjjlains  why  in  biserial  arms  the  pinnules  are  given  off  from  every 
j^lato  at  each  side  of  the  arm,  while  in  uniscrinl  arms  every  second  plate  at 
each  side  bears  a  pinnule. 

That  the  biseriol  arms  represent  the  higher  form  is  clearly  shown  by 


MOHl'IlOLOdlCAI.   I'AUT. 


71) 


thoir  mode  of  growth,  iiiitl  tlioir  griuliml  introduction  in  guologiciil  tiine. 
In  tlie  young  dit'yclic  Crinoid,  tin  wtt  liad  occasion  to  ob.-^crvt'  I'lpiMiiilly  well 
in  tho  genus  yv.<///o////'.v  (I'latt-  fiXXIIl  Fig.  10,  and  IMatu  LXXV.  Fig.  II), 
tlio  arms  ari>  unisorial  througliout,  their  outlines  waving,  the  plates  deciijediy 
wedge-sluiped,  tliu  |)innules  proportionally  largo  (.nd  gison  od"  alternately  as 
in  true  uni.serial  arniH.  in  xomewhal  older  npcc'inuns,  the  plates  at  the  tips 
gradually  interlock,  an<l  tliu  new  onuM  Htill  forming  at  the  di«tal  <'nd  are 
strictly  l)iserial.  With  advancing  maturity  the  interlocking  gradually  ex- 
tends to  the  prt)xiiuid  ends,  luitil  (iiially  in  the  adult  I'/ti///cniiiix  the  whole  arm 
becomes  hiserial,  excei)t  perhaps  as  to  a  few  plates  near  the  calyx,  whicli 
permanently  retain  their  larval  condition.  Similar  modilication-<  occurred 
in  geological  time.  In  the  Ijower  Silurian  the  nrms  of  monocyclic  Cainerata 
arc  uniserial,  almost  without  exci'ption.  In  the  Niagara  group  and  Wen- 
lock  limestone,  however,  they  rapidly  change  into  hiserial.  It  is  very  signi- 
ficant that  among  the  species  of  that  epoch  we  find  as  persistent  characters 
all  the  phases  through  which  the  arms  of  the  individual  Crinoiil  pass  in  early 
life.      This  is  well  u  in   the  case  of  the  IlatocrinidiC*     The  arms  of 

llulirorriiiits  and  h  lueiiiiiis  are  uniserial;  but  while  the  jdates  of  the 
former  are  always  rectangular,  those  of  the  latter  in  sonu>  species  are  de- 
cidedly cuneate.  The  same  modifications  can  be  observed  among  the  arms 
of  rulilll'icrmis  and  Sfi/iiliiuriiiiis,  but  in  8ome  of  their  Hpecics  the  cuneate 
plates  alrea<ly  begin  to  turn  into  biserial  by  interlocking.  We  thus  find  in 
the  same  genu."*,  anil  almost  contemporaneously,  all  the  variations  from  uni- 
serial arms  to  biserial ;  and,  what  is  most  significant,  the  arms  of  all  r)evo- 
nian  and  later  Uatocrinida>  are  stri(\tly  biserial.  Turning  to  the  I'latycriuida', 
we  find  that  the  Upper  Silurian  C"rif///i'Cniiiis  has  nni.serial  arms,  foinied  of 
rectangular  or  cuneate  joints,  while  in  Jfiirsii/nocri'iiiin,  Ciiiicocfinii.s,  and  I'/n/i/- 
crlniis  they  arc  biserial.  We  may  note  also  the  case  of  the  Ilexacrinida',  in 
which  the  development  of  the  arms  took  place  at  a  later  period.  The  arms 
of  the  Devonian  genus  IIi.racniniK  are  uniserial,  and  also  those  of  tlu'  earlier 
species  of  Dirhorriinix.  The  plates  of  the  latter  are  rectangular  in  all  Kinder- 
hook  species,  and  al.-JO  in  about  half  of  those  from  the  Burlington  and  Keokuk 
groups ;  in  mo.st  of  the  others  they  are  wedge-shaped,  and  ir  a  few  of  them 
the  arms  fairly  enter  the  interlocking  stage.  All  species,  liowever,  of  the 
Kasknskia  group  have  bi.serial  arms,  and  likewise  the  contemporaneous 
Tdlnrocfiniis  and  Plcrolorrimis.      Among  the  Melocrinida;,   GlnpiocriiniH  and 

•  Wf  linvp  scpnnitod  the  lliitdcriniilH'  from  thi,' Actiiiopriiiidir,  rcfiTrliig  to  llirin  only  (liosc  genera  in 
wliich  tlie  niiiil  |iliti'  is  followed  liy  llirec  iiitcrbrachiiil  pieces,  iiisleiul  of  two  ns  in  the  liilirr  family. 


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80 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


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Compsocriniis,  —  both  I'rom  the  Lower  Silurian,  —  have  uniserial  arms;  Pm- 
i/li/ptocyinns,  and  probably  all  later  Melocrinidaa,  biserial.  Among  dicyclic 
Canierata,  we  find  well  defined  biserial  arms  already  in  the  Trenton  and 
Hudson  River  groups,  aK)ng  witii  uniserial,  the  former  being  perhaps  in  the 
majority ;  but  the  latter  are  continued  to  the  lower  part  of  the  Devonian  by 
two  species,*  and  these,  together  with  the  species  of  Dichocrinus,  are,  so  far 
as  we  know,  the  only  representatives  of  the  Camerata  with  a  single  row  of 
arm  plates  that  survived  the  close  of  the  Silurian. 

In  the  Fistulata,  the  biserial  arm  structure  was  introduced  just  before  the 
close  of  the  Carboniferous,  but  only  in  a  limited  way.  True  biserial  arms 
only  occur  in  Gruphiocfiiws,-\  Euixichi/criims,  Cromi/ocvinus,  Hi/Jreionocnnus, 
Emoerinus,  Stemnvdocriniis,  and  IJncriints,  but  the  majority  of  species  have 
either  quadrangular  or  cuneate  arm  plates,  and  in  some  of  them  only  the 
tips  of  tlie  arms  begin  to  interlock.  In  this  group  the  biserial  stage  at  no 
time  became  a  constant  character,  not  even  in  the  Triassic.  Encrinus  lilii- 
formix  has  perfectly  biserial  arms,  while  the  arms  of  Encrinus  gracilis  are 
uniserial,  and  composed  of  quadrangular  plates. 

Tiie  arms  of  the  Articulata,  not  only  in  Palaeozoic  pinnuleless  forma, 
but  also  in  the  Neozoic  pinnule-bearing  ones,  are  uniserial  without  exception. 

The  pinnules,  as  happily  expressed  by  Carpenter,  are  repetitions  of  the 
arms  on  a  small  .scale ;  and  in  their  organization  morphologically,  and  to 
a  large  extent  physiologically,  closely  resemble  ordinary  arm  branches. 
They  are  short  branchlets  given  off  along  the  sides  of  the  arms,  but  ra'-ely 
reaching  their  tips,  and  are  usually  more  slender,  and  composed  of  longer 
joints.  The  pinnules  differ  from  arms  in  containing  the  fertile  portions  of 
the  genital  glands,  while  the  arms  lodge  the  genital  cords.  Like  the  arms, 
they  have  ambulacral  furrows  fringed  with  cilia,  by  means  of  which  particles 
of  food  coming  in  contact  with  them  are  carried  along  the  grooves  to  the 

*  Oelilert's  new  genus  Viameiiocrinus,  nnd  "  Rhoilorriiiu.i "  gonatoies  Miiller  (bolli  from  the  lower 
Devonian),  which  perhaps  belong  to  one  genus,  linve  diehotomizing  arms,  composed  of  sliort,  quadrangular 
plates. 

f  It  is  doubtful  if  the  name  Ornpliioerinus  can  be  retained,  according  to  the  general  rules  adopted  by 
naturalists,  as  it  was  incorrectly  dclined  by  deKouiuckaudLeUon.  The  type  has  small  infrabasals  hidden 
by  the  column,  and  the  position  of  the  anal  pinte  is  materially  different  from  that  given  by  the  Belgian 
writers,  which  probably  was  not  known  to  Trautschold  when  he  proposed  the  genus  Phialocrinns.  The  anal 
plate  of  Graphiorrinits  enrriiwitlfs,  dc  Koninck's  type,  rests  directly  upon  the  truncated  posterior  basal,  as 
we  observed  in  a  fine  specimen  in  our  collection,  exactly  as  in  Phhloerinua.  Tliere  is,  however,  a  slight  ob- 
jection to  Trautseliold's  name,  which  was  preoccupied  by  Eichwald  (Lethaia  Rossica  I,  n.  578),  but  the 
genus  was  founded  merely  upon  fragments  of  column.  That  Phialocrhus  jm/eits  has  two  costals,  and  Oraphio- 
criniis  enrrinoides  but  one,  may  not  be  of  generic  importance,  as  the  two  plates  of  the  former  are  equal  to  the 
one  of  the  latter,  which  evidently  form  a  syzygy. 


MORPHOLOGICAL  PART. 


81 


mouth.  In  their  normal  condition  the  pinnules  are  arranged  alternately  on 
opposite  sides  from  every  second  joint,  so  tliat  each  joint  bears  a  pinnule. 
When  the  interval  between  the  pinnules  is  greater,  wliich  is  frequently  the 
case  at  certain  parts  of  the  arms,  especially  among  recent  Crinoids,  this  has 
been  called  a  syzygy.  The  term  was  applied  by  Joliannes  Muller*  to 
the  immovable  union  of  two  arm  joints,  of  which  only  the  upper  one  is 
pinnule-bearing.  The  two  plates,  to  which  the  names  "  hypozygal "  and 
"  epizygal "  were  given,  —  the  Ir.ter  for  the  pinnule-bearing  one,  —  count  in 
the  alternation  of  the  pinnules  as  one  joint.  Their  apposed  faces  are  not 
necessarily  striated,  as  indicated  by  Muller,  being  sometimes  dotted  or 
smooth.  Smooth  syzygial  faces  have  '  een  observed  in  recent  Crinoids  only 
in  a  few  Comatuloa,  but  they  occur  quite  frequently  among  Palaeozoic  species. 
In  the  latter,  we  also  find  occasionally  a  succession  of  two  or  three  hypozygal 
joints  in  the  same  syzygy .t 

Syzygies  do  net  occur  among  Palaeozoic  Crinoids  at  irregular  intervals  as 
in  recent  ones.  Either  they  have  a  continuous  series  of  syzygies  through- 
out the  whole  arm,  as  in  the  Hoterocrinidas  and  a  few  genera  of  the  Came- 
rata,  or  there  is  one  syzygy  in  each  order  of  brachials,  which  is  formed 
by  the  two  proximal  plates.  The  latter  is  frequently  the  case  among  the 
Poteriocrinida),  Encrinidae,  and  also  in  the  Camerate  genus  Dkhocriiins.  In 
Dtchocrinm,  the  suture  between  the  syzygial  plates  is  very  close,  and  the  line 
of  union  more  faint  than  the  lines  of  adjoining  pLates.  In  the  Poteriocrinida} 
either  the  apposed  surfaces  are  flat,  or  the  hypozygal  plate  is  slightly  ex- 
cavated, and  the  epizygal  correspondingly  convex.  In  Encrinus  liUifonuis  the 
corresponding  faces  are  dotted  so  as  to  make  a  very  close  union.  Tlie  Poterio* 
crinidaB  may  have  one  or  two  costals  within  the  same  genus.  In  species  with 
two,  both  plates  together  take  the  form  and  size  of  the  one ;  and  this  rule 
applies  to  the  proximal  distichals  as  well.  That  the  two  plates  of  the  costals, 
as  well  as  those  of  the  distichals,  form  a  syzygy,  is  practically  shown  by  the 
pinnules,  which  in  species  with  but  one  costal  begin  with  the  first  plate  after 

•  Ucber  den  Bau  des  Pentacrinus  caput  inedusne  (Abhandl.  d.  K.  Akademic  der  Wissenseliaften,  Berlin, 
1843,  p.  315). 

t  The  term  "  syzygy  "  lias  also  been  used  by  some  writers  for  (he  immovable  union  of  the  nodal  stem- 
joints  with  those  next  below  them,  as  in  the  case  of  Pentacriiim.  Tills,  we  think,  is  not  in  accordance  with 
Miiller's  definition,  who  proposed  the  term  for  two  arm-joints  of  which  only  the  upper  is  pinnule-bearing, 
and  not  for  a  special  mode  of  union  between  plates  generally,  lladiated  and  dotted  surfaces  do  not  always 
imply  a  syzygy.  Such  faces  arc  found  among  Palaiozoic  Crinoids  very  frequently  on  the  ordinary  arm  plates, 
and  even,  as  in  Crotalocrinm,  between  the  plates  of  the  dorsal  cup.  The  union  between  the  syzygial  juijits  is 
nothing  but  an  ordinaiy  close  suture,  which  may  have  striated  or  smooth  surfaces. 


IP 


I  I 


:i' 


ii  II I  I  mmi 


82 


tup:  crixoidea  camerata  of  north  America. 


the  axillary ;  while  in  species  with  two  costals  the  first  pinnule  is  given  off 
from  the  second  distichal.  In  the  HeterocrinidaB,  in  which  the  syzygies  pre- 
vail throughout  the  whole  arm,  they  are  formed  in  most  of  the  species  by 
more  than  two  plates.  While  Epactocrinus  ymndia  has  but  one  hypozygal, 
Ildcrocnniis  ha?  two  or  more,  followed  by  the  epizygal  bearing  the  pinnule, 
which  in  this  group  might  be  properly  called  an  armlet.  A  similar  arm 
structure  is  found  among  the  later  Calceocrinid*,  and  also  in  the  Belemno- 
crinidoe.  In  Epadomims  f/randis  the  syzygies  are  especially  well  marked,  the 
epizygal  joints  being  wedged-shaped,  the  hypozygal  quadrangular,  and 
arranged  parallel  to  the  distal  faces  of  the  preceding  epizygal. 

In  some  groups  of  the  Fistulata  it  is  exceedingly  difficult  to  discriminate 
between  pinnules  and  armlets.  As  a  rule,  pinnules  are  more  delicate,  and 
are  given  off,  except  in  cases  of  syzygy,  from  successive  joints ;  while  most 
of  the  armlets  are  arranged  at  more  or  less  irregular  intervals  along  the  sides 
of  the  ordinary  arms,  and  are  usually  branching.  We  find  armlets  among 
the  Heterocrinidoe,  Belemnocrinidoe,  in  Bari/cnnus,  Botri/ocnnvs,  and  the  later 
Calceocrinidoo.  The  Cyathocrinidae  have  long  filiform  arms,  which  frequently 
dichotomize,  but  have  neither  armlets  nor  pinnules.  The  Anomalocrinida) 
have  branching  arms  with  pinnules.  The  latter  are  given  off  in  rows  from 
every  joint  at  one  side  of  the  arm  only  —  not  alternately  from  opposite 
sides  —  fron.  one  axillary  to  another,  reversing  their  position  in  the  succes- 
sive divisions.  The  HybocrinidaB,  svhich  represent  one  of  the  most  primi- 
tive forms  of  the  Fistulata,  possess  but  one  arm  to  the  ray,  and  have  neluier 
pinnule.'!  nor  armlets.  The  Catillocrinidcc  have  numerous  simple,  pinnuleless 
arms,  given  off  directly  from  the  radials,  without  the  interposition  of 
axillaries. 

In  the  Camerata  the  lower  brachials  take  part  in  the  calyx.  That  these 
plates  were  free  in  the  early  larva,  and  Avere  gradually  incorporated,  is 
clearly  indicated  by  the  ontogeny  of  recent  Crinoids,  as  well  as  the  phy- 
logeny  of  fossil  ones.  In  the  early  Pentacrinoid  larva  of  Antedon  the 
arms  are  free  from  the  radials  up,  and  the  costals  and  distichals  are  sub- 
sequently drawn  into  the  calyx  by  the  gradually  increasing  perisome.  This 
was  evidently  the  case  in  the  Camerata  also.  But  while  in  the  former  the 
perisome  consists  of  soft  tissues  encrusted  with  limestone  particles,  the  peri- 
some of  the  latter  is  formed  of  well-defined  plates.  Our  knowledge  of  the 
ontogeny  of  Camerate  Crinoids  is  of  course  limited;  all  we  know  is  that 
smaller  specimens  have  a  less  number  of  interbrachial  plates,  that  the  number 


\  \ 


MORPHOLOGICAL  PART. 


88 


increases  with  the  size  of  the  specimens,  and  that  with  the  increase  of  the 
latter  additional  brachials  are  incorporated  into  the  calyx.  We  have  found 
a  number  of  young  specimens  in  which  the  arms  are  free  from  the  first 
axillary,  but,  as  yet,  no  Acllnocrinus  or  likodomnus  in  which  there  is  not  at 
least  one  interbrachial. 

We  find  among  the  Camerata  a  large  number  of  transition  forms  in 
■which  the  costals  do  not  form  a  part  of  the  dorsal  cup,  and  the  first  inter 
radials,  to  a  large  extent,  are  interambulacral  in  position.  Such  is  the  case  in 
the  Platycrinidaj,  HexacrinidsR,  Acrocrinidoe,  and  Crotalocrinidoe.  In  Phiy- 
crimis  the  distal  ends  of  the  radials  are  provided  with  a  horse-shoe-shaped 
excavation,  which  closely  resembles  the  facets  of  the  Inadunate  Cyatho- 
crinidce.  This  facet,  which  in  some  species  extends  down  to  two-thirds  the 
length  of  the  plate,  rarely  takes  up  more  than  half  its  width.  It  is  occupied 
by  the  costals,  or,  when  these  are  very  small,  in  par<^^  also  by  the  first  dis- 
tichals.  The  costals  are  narrow,  and  resemble  in  form  and  general  appear- 
ance the  free  brachials  of  Inadunate  Crinoids.  They  are,  however,  not  free 
in  the  sense  of  these,  but  the  proximal  ends  of  one  or  both  plates  are  sutur- 
ally  connected  with  the  plates  of  the  tegmen,  so  as  to  be  immovable,  .and 
only  their  upper  ends  are  free  from  the  calyx. 

It  has  been  generally  supposed  that  there  was  in  Platycrimis  and  Dicho- 
crimis  an  articulation  or  loose  union  between  the  radials  and  costals.  This 
seemed  to  be  confirmed  by  the  presence  of  the  facet,  and  by  the  fact  that  in 
some  species  this  is  provided  with  a  sort  of  imperforate  transverse  ridge,  or 
angularity.  We  have  no  doubt  that  these  costals  were  movable  at  some 
period  of  life,  probably  in  the  larva  before  the  perisome  made  its  appearance, 
and  the  r>rals  still  rested  upon  the  beveled  edges  at  the  outer  ends  of  the 
radials.  But  it  is  equally  certain  that  the  plates  were  immovable  in  the 
adult,  owing  to  the  rigidity  of  the  interradial  and  covering  pieces,  with  which 
they  are  suturally  connected.  The  systematic  position  of  the  Platycrinidce  is 
intermediate  between  the  Inadunata  and  the  typical  Camerata.  They  repre- 
sent phylogenetically  an  early  stage  of  Actinoerinus,  Batocrinus,  and  their 
congeners;  but  are  nevertheless  true  Camerate  Crinoids,  for  their  lower 
brachials  are  fixed,  retaining,  however,  permanently  to  a  large  degree  the 
characteristics  of  free  arm  plates.  In  Ciilkocrmts  and  Plerotocrims,  the  one 
a  Platycrinoid,  the  other  a  Hexacrinoid,  the  Camerate  type  is  somewhat 
more  advanced,  as  their  costals  practically  enter  the  dorsal  cup ;  and  there 
are  a  few  species  of  Plati/crims  in  the  same  condition  (Plate  LXXI.,  Fig.  16). 


1  .' 


84 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


So  there  ia  nn  almost  uninterrupted  series  of  forms  from  the  Inadunata  to 
the  most  completely  developed  Camerata. 

It  has  been  stated  that  in  Dichocriims  the  various  orders  of  brachials,  to 
the  last  bifurcation,  consist  of  two  plates  each,  and  that  the  plates  of  each 
order  form  a  syzygy,  the  epizygal  bearing  an  arm  instead  of  a  pinnule.  A 
similar  structure  is  found  in  most  species  of  Plali/crinus  from  the  costals  up, 
and  although  the  union  between  these  plates  may  have  been  less  close  than 
in  Dichocrinus,  they  evidentlj'  form  a  syzygy,  except  in  cases  in  which  the 
first  plate  of  the  order  is  pinnule-bcving,  as  in  P.  Uunisvillcc  and  P.  Surce. 
It  is  very  significant  that  in  both  these  species,  and  a  few  others,  the  first 
pinnule  is  given  ofTfrji^  the  first  distichal,  and  the  second  on  the  same  side 
from  the  first  palmar,  thus  showing  that  the  arm  partakes  of  the  alter- 
nation of  the  pinnules ;  and  this  suggests  the  question  whether  all  arm- 
branches  are  not  enlarged  pinnules.  In  Eucladocriims,  which  is  actually  a 
highly  differentiated  Plaf^/criiius,  the  branches  are  given  off  alternately  from 
every  second  joint  up  to  the  end  of  the  rays,  exactly  like  the  pinnules  in 
cases  of  syzygy ;  but  while  in  PMi/crinus  the  axillaries  are  in  their  normal 
condition, — the  superior  faces  equally  divided, —  in  Eucludocrinus  they  are  of 
irregular  form.  They  resemble  enlarged  pinnule-bearing  plates,  of  which 
the  side  supporting  the  next  order  of  brachials  is  much  wider  than  that 
giving  off  the  arm  (Plate  LXXIV). 

There  can  be  but  little  doubt  that  in  Euchdocrims  the  lateral  arms  in  the 
young  Crinoid  were  pinnules ;  and  there  is  abundant  proof  that  this  was 
also  the  case  with  the  arms  of  other  groups,  as  is  well  shown  by  Glyptocrinui 
Dyeri,  In  most  species  of  Gbjptocrinus,  for  example,  G.  dceadadi/lus*  the 
second  bifurcation  takes  place  from  the  second  distichal.  In  G.  Dycri,  how- 
ever, this  plate  gives  off  from  one  side  in  place  of  an  arm  a  large  pinnule, 
more  than  twice  the  size  of  an  ordinary  one ;  and  a  second  pinnule,  but 
little  smaller,  starts  off  from  the  fourth  distichal  on  the  opposite  side.  Both 
pinnule-bearing  joints  have  nearly  the  shape  of  true  axillaries,  and  what  is 
most  remarkable,  the  arm  bends  outward,  forming  an  angle,  as  if  a  true  bifur- 
cation took  place.  (Pla^ie  XX.,  Fig.  1  a,  b,  c).  The  four  or  five  proximal 
pinnules  of  this  species  are  incorporated  into  the  calyx,  and  it  is  quite  evi- 
dent that  the  growth  of  the  armlets  —  or  pinnules,  whichever  they  are  — 
was  arrested  by  the  rapid  upward  growth  of  the  perisome.  All  succeeding 
pinnules  are  small,  and  given  off  alternately  from  successive  joints. 

*  This  species  has  twenty  arms,  and  not  ten  as  indicated  by  tlie  name. 


S     I 


MORPTTOLOGICAL  PART. 


86 


The  structure  of  this  species  is  a  very  strong  indication  that  the  arm 
branches  are  modified  pinnules ;  and  this  suggests  that  non-pinnule-bcuring 
brachials,  whether  fixed  or  free,  may  form  a  syzygy  whether  the  succeeding 
axillary  supports  an  arm  or  a  pinnule.  Carpenter  pointed  out*  that  among 
recent  Crinoids,  with  but  few  exceptions,  "  the  first  two  joints  beyond  every 
axillary  of  the  dividing  rays  are  united  to  one  another  in  the  samu  man- 
ner, either  by  syzygy  or  bifascial  articulation."  This  rule  seems  to  hold 
good  also  for  most  of  the  Pala;ozoic  Crinoids,  with  the  exception  that  we 
find  among  them  only  syzygies,  and  no  articulation. 

The  Actinocrinidae,  as  we  have  stated,  represent  an  advanced  stage  of 
the  Camerate  type.  Not  only  their  costals,  but  also  their  distichals,  and 
generally  several  more  orders  of  brachials,  participate  in  the  formation  of 
the  calyx,  and  all  the  branches  are  given  off  alternately  from  opposite 
sides  of  the  main  trunks.  In  the  genus  Aciinocnmis,  f  only  every  second 
or  third  brachial  of  each  order  in  the  calyx  supports  an  arm  (Plate  LX., 
Fig.  1«) ;  but  in  Caeioen'ntts,  Phijsdocrimis,  Tclciocrimis,  and  Slrotocyiims,  an 
arm  originates  from  each  successive  plate  (Plate  LXV.,  Figs.  !«  and  \c),  and 
the  arms  alternate  like  the  pinnules.  In  Ac/inocriiws  occasionally,  and  in  Am- 
phoracrimis  generally,  branches  are  also  given  off  at  irregular  intervals  from 
t'le  free  arms;  but  these  evidently  made  their  appearance  after  the  arms 
had  become  biserial.  In  Steganocrimis  the  branching  is  continued  to  the  top 
of  the  rays,  as  in  Eudadocrinus  (Plate  LXL,  Figs.  1«  and  \d),  and  each  order 
of  brachials  consists  of  one,  two  or  three  plates,  Avhich  are  formed  into  tubular 
appendages  of  the  calyx,  giving  oflf  biserial,  pinnule-bearing  arms.  Accord- 
ing  to  our  interpretation,  we  have  in  Adinocnnus  and  Sleganocrimts  a  series 
of  syzygies,  in  the  former  extending  to  the  top  of  the  calyx,  in  the  latter  to 
the  top  of  the  rays ;  as  opposed  to  Cadocrimis,  Strotocrimis,  etc.,  in  which 
each  order  of  brachials  consists  of  a  single  plate,  which  is  axillary. 

The  pinnules  of  the  Actinocrinidoa  differ  from  those  of  other  families  in 
being  provided  with  prominent  hooks,  directed  obliquely  upward  and  out- 
ward. These  hooks  are  arranged  in  rows  parallel  to  the  sides  of  the  arms, 
and  those  of  one  pinnule  overlap  the  corresponding  ones  of  adjoining  pin- 
nules (Plate  LVIII.,  Figs.  1  and  la,  b,  c),  so  as  to  give  to  the  mass  of  pinnules 
the  appearance  of  a  highly  complicated  network. 

•  Clmll.  Rep.  I.,  p.  49. 

t  We  subdiviilc  the  genus  Actinosrinus,  as  heretofore  recognized,  into  Actinocriiius  proper,  and  Carfo- 
criniis ;  referring  to  the  former  only  tlic  lobcd  speeies  with  two  or  more  brachials  to  cnch  order;  and  to  tlic 
latter  those  in  whicli  the  free  arms  are  arranged  equidistant  around  the  calyx,  and  each  order  of  brachials 
above  the  costals  consists  of  but  one  plate. 


86 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


If 


n 


I   I    f 


;    ; 


In  the  Biitocrinida),  we  find  an  arm  structure  such  as  occurs  in  no  other 
group.  While  in  all  other  Caincrata  the  anibulacral  t ironings  of  the  calyx 
give  origin  to  but  a  single  arm,  those  of  the  Batocrinitos  frequently  bear  two, 
either  from  every  opening  or  from  any  less  number  of  them,  and  this,  which 
is  very  remarkable,  even  in  the  same  species.  Thus  the  specimens  may  have 
eighteen  arm  openings  and  but  eighteen  arms,  or  any  number  from  eighteen 
to  thirty-six.  This  mode  of  multiplying  the  number  of  arms  is  found  only 
among  the  later  forms,  and  it  is  evident  from  the  structure  that  the  second 
arm,  where  it  occurs,  was  introduced  in  the  nearly  mature  individual  after  the 
arms  became  biserial,  and  the  lower  orders  of  brachials  had  been  incorporated 
into  the  calyx.  The  bifurcation  takes  place  in  the  same  manner  as  in  free 
biserial  arms,  there  being  no  true  axillary,  and  the  plate  taking  its  place 
is  no  larger  than  the  succeeding  arm  pieces. 

In  the  Batocrinidae,  all  branching  in  the  calyx  is  by  means  of  dichotomy, 
and  the  number  of  arm  openings  in  the  three  anterior  rays  rarely  exceeds 
four;  but  there  may  be  only  two  or  three,  and  in  the  posterior  rays,  the 
arms  next  to  the  anal  interradius  may  bifurcate  once  or  twice  again,  so  that 
two  of  the  rays  have  five  or  six  arm  openings.  In  some  genera  the  number 
of  arm  openings  varies  considerably  among  the  rays,  the  anterior,  or  occa- 
sionally the  antero-lateral  ones,  being  generally  the  least  developed.  This  is 
not  the  case  in  the  Actinocrinidao,  in  which  normally,  with  one  or  two  excep- 
tions, the  number  of  arms  is  equally  divided  among  the  rays.  In  the  Peri- 
echocrinites,  which  we  made  a  subdivision  of  the  Batocrinidae,  the  free  arms 
almost  always  branch  in  their  biserial  stage  ;  while  they  remain  simple  in 
the  Batocrinites. 

In  Mclocrinus  a  very  peculiar  arm  structure  occurs,  somewhat  similar  to 
that  of  Stcganocrimis  and  Eucludocrimts ;  but  while  in  the  latter  the  two  divi- 
sions of  the  ray  form  independent  appendages,  all  the  way  from  the  calyx 
up,  those  of  Mehcrinus,  either  for  some  distance  or  to  the  full  length  ot  the 
rays,  are  laterally  connected,  and  form  together  but  one  appendage,  from 
which  the  arms  are  given  ofiT  at  intervals  from  opposite  plates  in  the  ray, 
and  from  one  side  only  of  each  half. 

In  most  of  the  RhodocrinidfB  and  Thysanocrinidae,  the  arms  branch  in 
their  free  stage,  whether  uniserial  or  biserial.  The  arms  of  Ripidocrinus  are 
given  off  at  both  sides  of  the  main  rays,  as  in  Stet/anocnnKS  sculptus.  Those  of 
Gilbedsocnnus  are  very  delicate,  and  frequently  pendent.  The  latter  is  the 
case  also  in  some  species  of  Acrocriniis,  and  the  Swedish  genus  Banandeo' 


I 


MORPHOLOGICAL  PART. 


87 


cn'ntis,  in  which  they  completely  envelop  the  calyx,  exposing  their  ventral 
Burfacea. 

The  mobility  of  the  arms  in  the  Camerata  must  have  been  limited,  as  we 
nowhere  find  at  the  apposed  faces  of  the  various  brachials  any  trace  of  a 
muscular  attachment.  Those  brachials  which  take  part  in  the  calyx  arc, 
like  the  other  calyx  plates,  united  with  one  another  and  with  adjoining 
plates  by  close  suture,  the  apposed  surfaces  being  flat  and  generally  smooth, 
rarely  striated  ;  and  the  plates  are  immovable.  The  first  indication  of  any 
kind  of  articular  facet  occurs  on  the  highest  plate  of  the  calyx ;  i.  e.,  that 
bearing  the  free  arms.  This  plate  is  usually  more  or  less  concave,  often 
striated,  sometimes  having  a  sort  of  ball-and-socket  arrangement,  or  being 
provided  with  an  obscure  transverse  ridge ;  and  in  a  few  cases  it  is  perfo- 
rated. The  faces  of  the  higher  arm  plates  are  smooth  or  striated,  and  but 
little  concave ;  yet  there  must  have  been  a  considerable  amount  of  mobility 
even  among  them,  for  the  tips  of  the  arms  are  frequently  curved  inward,  and 
in  some  cases  the  arms  are  decidedly  spreading. 

The  mode  of  union  between  the  brachials  of  the  earlier  Fistulata  was 
similar  to  that  of  the  Platycrinidoc.  The  Dendrocrinida)  and  Cyathocrinido) 
have  more  or  less  well  developed  facets  upon  the  radials,  and  the  arm 
plates  are  united  among  themselves  and  with  the  radials  by  ligaments 
only,  so  as  to  admit  but  little  motion.  In  the  later  Fistulata,  however, 
notably  the  Poteriocrinida)  *  and  Encrinidas,  there  is  a  muscular  articula- 
tion between  the  axillaries  and  the  joint  succeeding  them,  as  in  recent 
Crinoids. 

The  Larviformia,  so  far  as  they  are  known,  have  a  well  differentiated 
muscular  articulation,  with  transverse  ridge  and  fossae  between  the  radials 
and  costals,  but  not  between  the  succeeding  brachials.  Ctiprcssocriims,  Alhffc- 
crinus,  and  Si/mbctthocrinus  have  large  muscle  plates  connected  with  the  radi- 
als ;  while  the  other  brachials  are  so  closely  united  one  to  another  that  it 
appears  as  if  the  whole  arm  had  mo     ''  rigidly  upon  the  radials. 

In  the  Ichthyocrinidao  all  the  brad  lals,  whether  fixed  or  free,  are  mov- 
able. The  calyx  was  pliable  from  the  radials  up,  as  is  shown  by  the  apposed 
faces  of  the  plates,  which  are  deeply  hollowed  out ;  not  only  those  of  the 
brachials,  but  the  interbrachial  plates  as  well.  Tlie  cavities,  which  evi- 
dently lodged  large  bundles  of  ligament,  contain  small  elevations  with  stri- 

*  It  is  unfortunate  that  the  genns  Poteriocrinus  has  been  made  the  type  of  tliis  family.  It  is  tlie  only 
genus  of  tlie  Poterioevinidte  in  wliich  the  facet  supporting  the  arms  is  horsc-shoe-.'liaped,  and  the  costals  do 
not  occupy  the  full  width  of  the  radials,  which  is  so  characteristic  of  the  family. 


*    \ 


' 


88 


THE  CRIXOIDKA  CAMERATA  OF  NORTH  AMERICA. 


!' 


Hf 


ated  faces.  Those  of  the  fixed  brnchiiilH  form  irregular  ridges,  which  proceed 
from  both  sides  of  tlie  phitcs  toward  the  middle  without  meeting.  The 
apposed  faces  of  tlie  free  arm  plates  have  been  rarely  observed,  but  ho  far  as 
known  they  are  more  or  less  concave,  and  we  have  found  on  some  of  them 
indications  of  transverse  ridges.  The  lines  of  imion  between  the  brachials 
generally  have  a  waving  outline,  and  many  of  the  species  have  a  sharp  pro- 
cess projecting  from  the  distal  end  of  tiie  plates,  which  fits  into  a  shallow 
depression  upon  the  outer  face  of  the  plate  below.  In  some  species,  especi- 
ally the  larger  ones,  this  projection  forms  a  separate  jtlate.  The  arms  of  all 
IchthyocriniduQ  are  uniserial,  the  joints  quadrangular,  and  they  are  destitute 
of  pinnules. 

II.    THE  PLATE-S  OP  THE  ACTINAL  SYSTEM. 
A.     T/w  Orals. 

The  orals  arc  not  always  represented  in  the  adult  Crinoid.  When 
present,  thoy  surround  the  mouth  or  cover  it;  and  they  may  occupy  the 
whole  face  of  the  ventral  disk,  or  only  its  median  portions.  In  the  former 
case  they  rest  upon  the  edges  of  the  radials ;  in  the  latter  against  the  peri- 
some.  In  Crinoids  with  a  regular  pentamerous  symmetry  tbey  consist  of  five 
pieces,  interradially  disposed,  and  occupy  the  centre  of  the  disk.  When  the 
symmetry  is  irregular,  they  are  pushed  more  or  less  toward  the  anterior  side. 
The  former  condition  prevails  among  the  recent  Crinoids,  and  in  the  Larvi- 
formia  ;  the  latter  is  the  general  rule  among  Palaeozoic  forms.  When  asym- 
metrical, the  posterior  oral  is  pushed  in  between  the  four  others,  and  is 
generally  larger  (Plate  III.,  Figs.  11,  17,  18,  20.  21,  22,  and  23). 

The  orals  are  among  the  earliest  plates  developed  in  the  larva.  They 
make  their  appearance  simultaneously  with  the  basals,  upon  which  they  rest 
until  the  radials  are  introduced,  when  they  occupy  the  beveled  upper  edges 
of  the  latter  plates.  In  the  larva  of  recent  Crinoids  they  form  a  pyramid, 
composed  of  five  nearly  equal  pieces,  which  at  first  are  laterally  united  and 
closed  at  the  top  ;  but  they  soon  open  out,  and  expose  the  tentacular  vesti- 
bule. At  a  more  advanced  stage  the  orals  are  carried  inward  by  perisome, 
until  finally  in  most  of  the  species  they  become  resorbed,  and  are  replaced 
by  upward  perisomic  growth.  In  only  a  comparatively  few  recent  fonns  do 
they  persist  through  life,  and  in  these  cases  they  occupy  the  median  portions 
of  the  disk,  and  enclose  the  oral  opening  (Plate  III.,  Figs.  9  and  10). 


MOIU'HOLOdlCAL   TAUT. 


80 


While  thus  among  recent  Criiioids  the  oriilM  are  readily  recognized,  their 
identiliciitiun  among  I'aUuozoiu  furnis  has  Ixh'Ii  tiie  Hiil)JL'ct  of  iniic.h  oontro- 
versy.  Allnian*in  18GJ  expreMscd  tiie  ojiinion  tiiat  the  group  of  platew  In 
the  centre  of  tlio  vault  of  niuny  PaUeocriiioids  is  a  reprcsontative  of  the  sim- 
ple oral  system  of  the  young  Cvinaliild  ;  but  as  those  plates  oftun  consist  of 
more  tlian  five,  it  was  not  made  clear  to  which  particular  ones  his  homology 
applied.  In  most  Palffiozoic  Crinoids  tliero  is  no  oral  opening,  and  the 
arrangement  of  tho  plates  at  the  summit  is  irregular  and  ({uite  varial)le. 
This  is  tho  case  particularly  among  the  Camerata,  in  which  the  median 
portions  of  the  disk  are  generally  occupied  by  a  largo,  centrally  located 
plate,  surrounded  by  eight  or  nine  others,  of  which  four  are  large  and 
similar  in  form  and  size.  These  four  larger  plates  are  directed  toward 
tho  anterior  side  of  tho  disk,  forming  at  their  outer  edges  re-entering 
angles,  which  are  fdled  by  three  rather  large  plates,  radially  disposed ; 
while  the  four  or  five  smaller  plates  of  the  proximal  ring  are  directed 
posteriorly,  and  are  followed  by  numerous  more  or  less  irregular  pieces, 
directly  or  indirectly  connected  with  tho  anus  (Plate  III.,  Figs.  17,  18,  20, 
21,  22,  and  23).  Occasionally  tho  larger  plates  are  separated  from  one 
another  by  small,  supplementary  pieces  (Plate  III.,  Fig.  23).  This  is  the 
case  in  some  of  the  larger  species,  in  which  the  small  pieces  were  intro- 
duced in  the  growing  Crinoid.  There  are  also  species  in  which  the  larger 
plates  are  not  represented  at  all,  and  the  whole  ventral  disk  is  composed 
of  minute  pieces  without  definite  arrangement,  leaving  only  an  opening 
for  the  nnus  (Plate  III.,  Fig.  24). 

The  interpretation  of  these  plates  has  proved  tho  more  difficult  because 
in  other  groups,  notably  the  Larviformia,  the  tegmen  consists  of  but  few 
pieces,  which  have  a  dilTerent  arrangement.  In  Alltiffccnnus  and  Myrtilo' 
criniis  (Plate  III.,  Fig.  13),  the  whole  ventral  surface  is  covered  by  five  large 
interradial  plates,  resting  upon  the  superior  edges  of  tho  radials,  exactly  as 
the  orals  in  the  Pentacrinoid  larva  of  Antedon.  Ilaphmims  (Plate  III.,  Fig. 
14)  has  five  similar  plates,  which  were  at  one  time  supposed  to  surround  a 
small  central  plate.f  Si/mhathocnims  (Plato  III.,  Fig.  25)  has  a  pyramid  of 
five  large  plates,  four  of  them  resting  upon  the  edges  of  the  muscle  plates  of 
the  radials,  and  partially  surrounding  a  larger  one,  wedged  in  from  the  pos- 


•  Trans,  noy.  Soc.  Edinb.  Vol.  XXIIT.,  pp.  245-251. 

f  Our  supposed  discovery  of  this  plate  in  a  specimen  of  Haplocriniia  meipitiformis  proved  nftcrwnrds  to 
be  a  mistake,  due  to  the  peculiar  fractures  in  tlie  speeinicn.     Carpenter,  to  whom  wc  submitted  the  specimen, 

13 


in 


90 


TIIK  CHIXOIDKA  CAMKRATA   OF  NORTH  AMKRICA. 


1 


. 


■l^ 


tcrior  sitlo  to  a  nearly  central  position.  Tlio  deHcription  of  the  vcntriil  plates 
of  th'm  genim  in  tiiu  Ik-vision,  Part  HI.,  p.  87,  waH  incorrect  im  to  the  small 
pieces  around  the  five  Huintnit  platcH,  the  appearance  of  which  waH  produced 
by  cracks  and  not  sutures.  SpecinienH  of  better  prenervation  show  pomtively 
that  tiio  ventral  surface  is  occupied  exclusively  hy  the  five  largo  platcH. 
Pindcriniis,  as  shown  by  a  Hpecinicn  of/*.  j>iliilu  in  our  poHHession  from  Dudley, 
England,  has  a  similar  structure.  Among  the  Caraerata  five  largo  sunnuit 
plates  are  known  to  exi.'*t  onl_>  in  Coccocriims  and  Ciilicocri'tnis,  the  plates 
of  the  former  being  equal  (Plato  III.,  Fig.  14),  those  of  the  latter  slightly 
unequal. 

As  tho  largo  central  plate,  when  it  occurs,  occupies  approximately  the 
same  position  as  tho  oral  opening  of  recent  Crinoids,  it  seemed  plausible  that 
the  orals,  if  present  at  all,  should  bo  looked  for  in  tho  Cainerata  among  tho 
plates  of  tho  proximal  ring  ;  but  on  examining  tho  structure,  it  was  found 
that  only  tho  four  larger  plates  could  bo  compared  with  tho  five  orals  of 
recent  forms ;  so  the  question  arose,  what  had  become  of  tho  corresponding 
fifth  plate? 

Wachsmuth,  in  1877,*  directed  attention  to  the  two  plates  of  the  same 
ring  adjoining  tho  four  larger  ones,  and  suggested  that  these  two  plates 
taken  together  were  probably  equivalent  to  ono,  being  split  into  two  by  the 
anu.s,  and  that  tho  six  plates  represented  morphologically  but  five.  The 
plates  were  not,  however,  regarded  by  him  as  the  orals ;  ho  thought  the 
whole  ventral  covering  of  tho  earlier  Crinoids  was  structurally  distinct  from 
the  disk  of  recent  ones. 

A  similar  view  of  the  subject  was  taken  by  us  in  the  following  year.f 
We  assumed  that  the  plates  of  the  dorsal  cup  and  those  of  the  tegmen  were 
parallel  structures ;  that  the  central  plate  was  represented  in  the  dorsal  cup 
or  abactinal  side  by  the  infrabasals,  the  six  proximals  by  the  basals,  and  that 
other  plates  of  the  tegmen  represented  the  radials  and  interradials.  No 
comparison  was  then  made  by  us  of  these  plates  with  the  plates  in  the  disk 
of  recent  forms ;  but  this  was  done  in  1881,:j:  when  we  suggested  that  the  six 
proximals  represented  the  orals. 

Dr.  P.  H.  Carpenter,  like  o'lrselvea,  recognized  in  the  Canierata  a  central 
plate,  for  which  he  proposed  the  name  "  oro-central,"  and  six  proximals 

veriQed  our  observiition,  and  held  the  plate  to  be  homologous  with  the  so^nllcd  central  plate  of  the  Camerata, 
(Cliall.  Rep.  on  the  Stalked  Crinoids,  p.  158). 

•  Amer.  Joiirn.  Sci.  and  Arts  (series  3),  Vol.  XIX.  pp.  186-187. 

t  Revision,  Tart  I.,  p.  28. 

{  Revision,  Part  II,  p.  17  (Proceed.  Acad.  Nat.  Sci.  Phila.,  p.  191). 


MORPIlOLOCflCAL   PART. 


01 


Rurrouiuling  it.  IIo  rogiinltnl  the  forinur  ns  tlio  uctiiinl  reprcHontativc  of  tlio 
(loD'o-centriil  or  turiiiiiiul  plntu  uf  the  ntum,  mid  tiiu  latter  tiio  repreHcntntiveH 
of  the  hnmiln.  He  took  the  pi'o.xiiiialH  tu  he  tlie  uiiiIh,  heUeviiig  with  \\n  that 
the  poMterior  oral  wa8  divided  into  two  phiteit.  He  miid;*  ''The  proximal 
dome  phitcH  rent  directly  agaitiHt  the  calyx  interradiaU,  that  on  the  poHterior 
Bide  being  reprenented  by  two  Hniall  plates  with  the  anus  between  them; 
while  there  is  a  more  or  less  tidjercular  ring  of  radial  dome  plates  outsido 
them.  Theso  proximal  dome  plates  thus  correspond  exactly  to  the  orals  of 
Symlialhocriniis  and  Jlajilocrinun,  covering  in  the  peristome,  and  resting  against 
the  calyx  plates,  which  in  Vlafycrinus  are  the  interradials,  and  not  the  upper 
edges  of  the  radials,  as  in  the  simpler  forms.  ...  I  cannot  see  what  other 
view  can  ho  taken  of  the  proximal  dome  plates  which  immediately  surround 
the  oro-central,  than  to  regard  them  as  orals ;  /.  <•.,  as  the  actinal  representa- 
tives of  the  basals,  like  the  corresponding  plates  in  Si/mhathocriitus.  If  this 
bo  admitted,  it  follows  that  the  proximal  dome  plates  of  all  Plntycrinido), 
Actinocrinldoa  and  Rhodocrinido)  arc  also  homologous  with  the  orals  of  Nco- 
crinoids."t  Carpenter's  oral  theory  was  based  almost  entirely  upon  the 
hypothetical  oro-central,  —  a  plate  before  unknown  in  Echinoderm  morpho- 
logy, —  and  the  six  proximal  plates,  which  he  assumed  to  be  orals,  although 
their  morphological  relations  had  never  been  established. 

The  same  view  of  the  question  was  also  taKen  by  Etheridge  and  Car- 
penter,t  and  afterwards  by  Neumayr;§  while  Zittel  ||  supposed  the  orals 
to  be  unrepresented  in  all  Platycrinido),  Actinocrinidoo,  Rhodocrinido),  and 
Calyptocrinidiu ;  though  admitting  their  presence  in  some  of  the  other 
groups. 

The  above  theory  was  laid  aside  by  us  in  1885,  when  we  ascertained  that 
the  two  smaller  proximals,  which  we  had  supposed  to  represent  the  posterior 
oral,  occupy  a  radial  position,  and  therefore  could  not  be  orals.  The  struc- 
ture shows  that  these  plates  undoubtedly  represent  the  two  posterior  radial 
dome  plates,  pushed  to  a  position  amoii.cr  the  plates  of  the  proximal  ring  by 
the  anus,  the  three  anterior  ones  retaining  their  position  within  the  re- 
entering angles  of  the  four  larger  proximals.  This  discovery  was  announced 
by  us  in  Part  HI  of  the  Revision,  p.  47,  and  we  designated  the  respective 

•  Clmll.  Rep.  Stalk.  Crin.,  pp.  170  to  171. 

t  Dr.  Carpenter's  vie^s  on  this  subject  arc  fully  set  forth  in  the  Chall.  Rep.  Stalk.  Crin.,  pp.  158 
to  184. 

I  1880.    Catalogue  of  the  Blastoidcn,  pp.  06  to  76. 
§  1889.    Die  Stiimme  des  Thicrreiclies,  p.  418. 

II  Haudb.  der  Folieont.,  I,  p,  333. 


t\ 


92 


tup:  crinoidea  camerata  of  north  America. 


plates  by  the  letters  "  rx  "  in  the  accompanying  diagrams.*  There  now  re- 
mained among  the  plates  of  the  proximal  ring  but  four  which  could  possibly 
bo  taken  for  the  orals ;  and  this  led  us  to  inquire  whether  the  central  plate 
alone  might  not  be  a  coalesced  representative  of  the  five  orals  of  recent  forms. 

From  internal  casts  we  observed  that  this  plate  occupies  the  centre  of 
radiation,  and  that  not  only  the  ambulacra,  but  also  the  nerve  cords,  meet 
beneath  it.  It  was  this  structure  principally  which  led  us  to  the  assumption 
that  the  central  plate  represented  the  five  orals  collectively,  and  that  the 
four  large  proximals,  and  two  smaller  ones,  were  interradial  "  vault "  plates, 
corresponding  with  the  first  interradials  of  the  abactinal  side.  This  seemed 
to  us  the  more  probable,  as  in  the  dorsal  cup  a  division  of  the  first  interra- 
dial into  two  halves  by  an  anal  plate  is  a  frequent  occurrence  among  Palaeo- 
zoic Crinoids.  It  also  seemed  to  explain  why  in  Ilaploerimis  and  allied  forms, 
in  which  there  is  no  anal  plate,  the  central  piece  seemed  to  be  surrounded 
by  five  plates  instead  of  six,  supposing,  as  before  stated,  that  IIa^)locrintis  had 
a  small  oral  surrounded  by  five  interradial  plates,  and  Allagecrinus,  Coccocnnns, 
and  Ciilicocri'inis  five  interradials,  but  no  orals.  In  this  we  differed  from  Gotte, 
Carpenter,  Zittel,  and  Neumayr;  who  all  agreed  that  the  Schciiclplaticn  were 
the  orals.t 

This  was  the  state  of  the  question  in  1888,  when  we  came  into  posses- 
sion of  a  very  large  number  of  fine  specimens  of  Ilaplocnmis  mcspillformis 
in  various  stages  of  preservation,  and  found  to  our  astonishment  that 
such  a  thing  as  a  "central"  plate  does  not  exist  in  the  genus.  We  now 
sow  that  the  ventral  disk  consists  of  but  five  large  plates;  that  we  had 
mistaken  a  mere  fracture  for  a  suture ;  and  that  the  part  which  we  sup- 
posed to  be  a  separate  piece  was  a  tongue-like  prolongation  of  the  posterior 
plate,  projecting  in  between  the  other  four  plates,  and  sometimes  surmounted 
by  a  small  node  (Plate  III.,  Fig.  12J).  This  discovery  left  no  room  for  doubt 
that  the  large  ventral  plates  of  Ilaplocrinus,  and  of  the  Laviformia  generally, 
actually  represent  the  five  plates  composing  the  unopened  oral  pyramid  of 
the  Pentacrinoid  larva  before  it  moved  away  from  the  radials,  as  had  been 
contended  by  Carpenter  and  Goette. 

So  long  as  a  central  plate  was  recotrnized  in  Ilaplomntis,  we  saw  good 
reason  to  believe  in  the  existence  of  a  similar  plate  in  other  groups  of  the 

•  Revision,  Part  III.  Plate  VII.  Figs.  2,  3,  4,  5,  6,  8,  9,  10,  and  Plate  VIII.  Pigs.  1  and  2. 

t  Our  theory  of  the  iclations  of  the  summit  plates,  in  conformity  with  these  views,  was  discussed  in  the 
Revision,  Part  III.  pp.  44  to  59,  and  afterwards  in  greater  detail  in  our  paper  on  the  Summit  Plates,  in  the 
Proceedings  of  the  Academy  of  Natural  Sciences,  Philadelphia,  March  39,  1SS7. 


MORPHOLOGICAL  PART. 


93 


Palaeocrinoidea ;  but  as  soon  as  it  appeared  that  there  is  no  such  plate,  it 
occurred  to  us  that  tlie  plate,  so  apparently  central  in  many  Platycrinidoo 
and  ActinocrinidoD,  might  be  a  posterior  oral,  pushed  inward  to  a  central 
position  by  dnal  structures.  This  interpretation  seemed  to  us  one  of  the 
greatest  force,  more  likely  than  any  other  to  answer  the  conditions  of  a  valid 
homology,  and  to  remove  the  principal  objections  that  had  been  brought 
forward  by  Carpenter  and  ourselves  respectively  to  other  theories. 

The  idea  of  referring  the  plate  to  the  orals  was  not  altogether  new.  We 
had  already  taken  it  into  consideration  before  we  knew  the  real  structure  of 
Uaplocrimis,  and  alluded  to  it  in  the  Revision,  Part  III,  p.  5G,  as  follows :  "  A 
far  less  objectionable  interpretation  of  the  central  plate  than  that  given  by 
Carpenter  would  be  to  regard  it  as  a  posterior  oral.  In  this  case  the  orals 
would  be  represented  by  five  plates,  and  not  by  six ;  the  anus  would  be 
placed  outside  the  oral  ring,  and  the  radial  dome  plates  would  occupy  the 
same  position  towards  the  orals  as  the  calyx  radials  toward  the  basals.  But 
it  would  place  the  mouth  underneath  the  posterior  oral,  and  it  offers  no 
explanation  of  the  central  piece  in  Ilajilocriints."  The  last  of  these  diffi- 
culties which  then  seemed  so  serious  was  met  by  the  elimination  of  the 
mythical  plate  in  Uaplocrimis;  and  the  first  was  destined  to  be  perfectly 
cleared  up  by  the  recovery  of  a  new  fragment  from  the  scattered  pages  by 
which  Nature  unfolds  her  palajontological  story  to  us. 

While  writing  up  the  observations  which  we  had  made  on  Ilaplomims,  we 
made  another  still  more  unexpected  and  striking  discovery,  which  in  our 
opinion  settled  the  oral  question  in  conformity  with  the  last  mentioned  sug- 
gestion beyond  all  controversy.  Up  to  that  time  the  ventral  structure  of 
the  IchthjfocrinidoD  had  been  almost  totally  unknown.  By  extraordinary 
good  luck  ve  obtained  a  specimen  of  the  genus  Taxocriims  with  the  ventral 
disk  in  alnost  perfect  preservation,  and  after  carefully  cleaning  the  speci- 
men, we  found  that  it  had  an  external  month,  mirroumled  hy  five  parted  oral  plates, 
nith  the  ambulacra  convergwf/  to  it,  and  passing  in  between  the  orals.  (Plate  III., 
Fig.  11.)* 

The  middle  of  the  disk  is  occupied  by  five  rounded  or  very  obtusely 
polygon.al  plates,  interradially  disposed,  rather  oval  in  outline.  The  two 
antero-lateral  plates  are  tolerably  good-sized,  and  the  postero-lateral  ones 
slightly  smaller.     The  posterior  plate  is  nearly  three  times  as  large  as  any 

•  A  full  nccoiiut  of  this  unique  specimen  was  given  by  us  in  a  paper,  "  Discovery  of  tlic  Ventral  Struc- 
ture of  Taxocrinua  and  Hnploerinua,  and  Consequeul  ModiQcations  in  the  Classification  of  the  Crinoideo." 
Proceed.  Acad.  Nat.  Sci.  Phila.,  Nov.  27,  1888. 


i! 


H 


Ill 


94 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


of  the  others,  and  almost  twice  as  long  as  wide,  extending  well  in  between 
the  two  postero-lateral  plates. 

The  positions  of  these  plates  are  relatively  identical  with  those  of  the  five 
plates  at  the  summit  in  certain  forms  of  Plati/crinus,  such  as  are  illustrated  on 
Plate  III.,  Figs.  16  and  17,  except  that  the  plates  of  Tuxocnnus  do  not  meet 
in  the  centre,  but  leave  a  slightly  excentric,  obtusely  pentagonal  oral  open- 
ing, transversely  elongated,  its  longest  side  next  to  the  posterior  i^late.  Into 
this  opening,  which  is  deep,  the  ambulacra  converge,  and  turn  downwards  at 
the  five  corners. 

That  the  five  plates  of  this  .specimen,  although  somewhat  unequal  in  size, 
represent  morphologically  the  five  orals  of  the  recent  genera  Rhkocrimis, 
H>/ocrinus,  and  IIolopus,  nobody  will  deny  after  seeing  the  specimen.  And  a 
comparison  of  these  plates  with  the  so-called  central  plate  and  four  large 
proximals  in  Plnti/cnmis,  Adinocrimis,  etc.,  leaves  no  room  for  doubt  that  these 
are  likewise  true  orals.  The  arrangement  of  the  plates  in  the  different 
groups  is  practically  the  same  ;  the  only  difference  is  that  in  some  they  are 
less  symmetrically  disposed  than  in  others.  In  Taxocrinus,  the  anus  is  well 
removed  from  the  oral  centre,  which  accounts  for  the  fact  that  the  arrange- 
ment of  its  orals  is  rather  more  symmetrical  than  in  most  of  the  Camerata? 
in  which  the  anus  is  more  or  less  subcentral,  and  surrounded  by  heavy,  rigid 
plates.  That  the  amount  of  asymmetry  depends  upon  the  condition  of  the 
anus  is  cleai'ly  shown  by  the  figures  on  Plate  III.  Wiien  the  anus  is  excen- 
tric, and  its  plates  are  small,  the  arrangement  of  the  oruls  is  comparatively 
symmetrical ;  but  when  it  is  subcentral,  and  especially  when  it  is  extended 
into  a  lai'ge  tube,  the  orals  are  pushed  over  to  the  anterior  side.  In  Haph- 
erimts,  in  which  the  anus  penetrates  the  orals,  and  in  Coccocrimts,  in  Avhich  it 
occupies  the  arm  regions,  the  oral  pyramid  is  naturally  about  symmetrical.  It 
is  now  easy  enough  to  understand  how  a  set  of  five  plates,  synnnetrically  dis- 
posed over  the  mouth,  could  be  so  altered  by  the  introduction  of  anal  plates 
as  to  bring  the  mouth  and  centre  of  radiation  beneath  the  posterior  plate. 
By  the  encroachment  of  the  anal  plates  the  posterior  oral  was  pushed  to  a  cen- 
tral position,  and  thereby  the  mouth  came  to  be  placed  beneath  that  plate. 

The  above  explanation  of  the  orals  in  the  different  groups  met  the 
prompt  approval  of  Carpenter,  and  this  ended  a  long  controversy  Avhich 
had  been  going  on  between  us  for  over  six  years.  The  orals  were  found 
at  last  to  consist  of  four  of  the  proximals  which  he  had  claimed,  with  the 
addition  of  the  so-called  central  plate  which  we  had  contended  for. 


I  II 


MORPHOLOGICAL  PART. 


95 


It  remains  to  consider  the  views  of  Neumayr.  As  already  stated,  he 
agreed  with  Carpenter  that  the  ScheitclpMtcn  oi Haplocn'nus,  and  the  six  proxi- 
mals  of  the  Camerata,  represent  the  orals.  He  also  believed  in  the  prencnce 
of  a  central  plate  within  the  oral  ring  in  both  groups.  But  he  differed 
both  from  Carpenter  and  us  as  to  the  plates  representing  the  orals  in  the 
CyathocrinidoB. 

The  structure  of  the  ventral  disk  of  Ci/athocrims  exhibits  considerable 
variability,  and  a  comparison  of  the  various  plates  among  the  different 
species  is  by  no  means  an  easy  matter.  As  a  rule,  there  are  four  large 
interradial  plates  located  ventrally,  resting  upon  the  inflected  upper  edges 
or  limbs  of  the  radials,  and  at  the  posterior  side  two  narrow  longitudinal 
strips,  which  enclose  a  large,  perforated  madreporic  plate  lying  in  front  of 
the  ventral  sac,  and  whose  lower  (outer)  edge  is  in  contact  with  the  sac. 
The  plates  are  laterally  united  by  suture,  and  leave  five  well  defined  grooves 
which  are  occupied  by  the  ambulacra.  Within  these  plates,  towards  the  oral 
centre  and  covering  it,  there  is  a  variable  number  of  other  large  plates,  often 
of  the  most  irregular  arrangement,  varying  in  form  even  in  the  same  species, 
and  in  some  cases  exhibiting  the  asymmetry  of  the  orals  in  the  Camerata. 
The  difficulty  of  ascertaining  the  morphological  relations  of  these  plates  in 
the  different  forms  is  increased  by  the  fact  vhat  the  surface  of  the  outer 
plates  —  those  nearest  the  radials  —  is  covered  by  numerous  minute  peri- 
somic  pieces,  interposed  between  the  ambulacra.  The  ambulacral  plates 
consist  of  side  plates  and  covering  pieces. 

Neumayr  *  speaks  of  only  one  ring  of  plates,  resting  against  the  radials 
and  surrounding  the  mouth,  and  he  assumes  that  the  disk  of  Ci/athomims 
is  morphologically  in  the  condition  of  Haplocrinus,  except  that  the  ambu- 
lacra in  the  latter  are  subtegminal,  but  tegminal  in  the  other.  We  have 
illustrated  on  Plate  III  the  ventral  structure  of  Ci/aihocrinns  by  a  series 
of  specimens  of  different  geological  ages,  and  in  various  stages  of  preser- 
vation, which  show  that  the  disk  is  composed  of  two  sets  of  plates,  the 
one  within  the  other,  and  that  in  cases  where  but  one  ring  is  visible  the 
plates  of  the  second  are  covered  by  other  structures,  or  have  been  resorbed, 
or  are  not  preserved  in  the  specimen.  It  is  evident  that  Neumayr  has  in 
some  instances  confounded  the  plates  of  one  ring  with  those  of  the  other. 

Examining  first  the  two  specimens  of  C.  Gilesi{¥ig9.  1  a,h),  there  appears 
to  be  but  one  ring  of  plates,  and  these  rest  against  the  radials.    In  Fig.  1  a 


;;  *     ' 


*  Die  Stamme  des  Thierreicliea,  pp,  419-452. 


m 


96 


THE  CRIXOIDEA  CAMERATA  OF  NORTH  AMERICA. 


V 


\  y 


!l 


those  plates  are  completely  exposed,  in  Fig.  1  b  partly  covered  by  marginal 
pieces  ;  but  in  both  of  them  there  is  at  the  middle  of  the  disk  a  moderately 
large  vacant  space,  which  in  perfect  specimens  is  tightly  closed  by  additional 
plates.  C.  brevisacculus,  Fig.  2,  has  two  rings  of  plates:  an  outer  one,  com- 
posed of  five  subtrigonal  pieces,  of  which  the  posterior  one  is  largest  and  per- 
forated, and  an  inner  one,  composed  of  five  pairs  of  plates  nearly  as  largo  as 
the  former  but  of  variable  size  and  form,  which  meet  in  the  centre,  so  as  to 
close  the  mouth  and  peristome.  The  ambulacra  are  exposed  all  along  the 
plates  of  the  outer  ring,  but  are  covered  by  the  plates  of  the  inner.  In 
C.  noilosus.  Fig.  3,  and  C.  muUihrachiatus,  Fig.  4,  the  four  large  interradial  plates 
above  the  radials,  which  in  the  preceding  figures  are  wholly  or  partly  exposed, 
are  completely  hidden  from  view  by  small  marginal  pieces.  The  middle  of 
the  disk  is  covered  by  a  nuniber  of  rather  large  pieces,  even  more  irregular 
in  their  arrangement  than  those  of  C.  brevisacculus.  The  ventral  disk  of  Euspi- 
rocrinus  xpintUs,  Fig.  5,  has  at  four  sides  a  very  large,  convex  interradial  plate, 
and  at  the  posterior  side  an  unusually  large  ventral  sac,  with  a  small  madre- 
porite  at  its  base ;  the  ambulacra  are  tegminal ;  and  the  median  portions  of 
the  disk  are  closed  by  moderately  small,  elongate  plates,  arranged  in  rows 
with  the  side  pieces,  which  meet  in  the  centre.  Very  different  is  the  disk  of 
Ci/alhicrinus  alutaceus,  Fig.  6,  which  has  at  the  summit  five  large  plates,  in  form 
and  arrangement  resembling  the  orals  of  Plafi/crinus.  The  posterior  one  is 
largest,  subcentral  in  position,  and  pushed  in  between  the  other  four.  There 
are  no  grooves  along  the  lateral  margins  of  tl  plates,  the  ambulacra  being 
subtegminal ;  but  the  re-entering  angles  at  inc  lower  end  enclose  five  well 
proportioned  radial  dome  plates. 

Comparing  the  summit  structure  of  C.  ahfaceus  with  that  of  the  Camerata, 
it  is  quite  evident  that  the  five  large  plates  of  Fig.  6  represent  the  so-called 
central  plate  and  the  four  larger  proximals.  This  was  also  the  opinion  of 
Noumayr ;  but  while  we  take  all  five  plates  to  be  orals,  he  clung  to  the  idea 
of  a  central  plate,  and  recognized  six  orals,  assuming  that  two  of  the  radial 
dome  plates  represented  the  posterior  oral.  We  do  not  see  how  those  plates, 
which  occupy  the  median  portions  of  the  disk  and  cover  the  mouth  and  ends 
of  the  ambulacra,  can  be  the  morphological  representatives  of  the  plates 
which  in  Figs.  1,  2,  and  5  rest  upon  the  radials.  Neumayr  took  the  two 
structures  to  be  equivalent,  while  we  believe  that  the  plates  of  the  former 
represent  the  orals,  and  that  the  latter  are  accessary  pieces  of  a  similar 
origin  to  the  interradial  plates  of  the  Platycrinidce. 


MORPHOLOGICAL  PART. 


97 


According  to  Neumayr,  the  disk  of  Cijalhocrinm  is  composed  of  five  large 
plates,  which,  like  the  SchcitdpMten  of  JIuplocrinus,  abut  against  the  radials. 
The  plates,  he  thinks,  are  in  sutural  contact  laterally,  but  leave  at  the  sum- 
mit a  large  space  for  t''e  mouth.  The  ambulacra  are  exposed  upon  the  sur- 
face, resting  within  the  deep  grooves,  formed  along  the  lateral  margins  of  the 
plates.  They  extend  from  the  mouth  to  the  bases  of  the  arms,  and  are  cov- 
ered by  small  plates,  which  project  inward  over  the  peristome,  and  close  the 
mouth  externally.  The  small  marginal  plates,  which,  as  he  states,  in  some 
species  extend  over  the  whole  disk,  he  takes  to  be  "  eine  secundiire  Wuche- 
rung  "  of  the  side  and  covering  pieces. 

His  description  does  not  agree  with  our  idea  of  Cijdhocrimis ;  it  comes 
closer  to  the  structure  of  Easpirocrimts  spiralis,  from  which  it  was  probably 
made.  The  latter  really  seems  to  have  but  one  set  of  large  plates  upon 
the  disk,  which  touch  the  radials,  and  enclose  at  the  summit  moderately 
small  plates,  which  may  be  ambulacral  pieces  ;  but  the  former  are  not  ovals. 
Cijathocnmts  Gilcsi,  as  represented  in  our  figures,  has  also  but  one  ring;  but 
there  is  a  large  vacant  space  at  the  middle,  which  was  evidently  closed  in 
more  perfect  specimens  by  an  inuer  ring  of  plates,  as  in  the  other  species. 
C.  brcvisnccuhts  has  an  outer  ring  of  plates  and  an  inner  one,  and  the  ambu- 
lacra, which  are  exposed  upon  the  former,  are  hidden  by  the  latter.  In  C. 
mnlllbrachiatus  the  outer  ring  is  covered  by  marginal  plates,  the  inner  rep- 
resented by  a  few  irregular,  large  pieces,  scattered  upon  the  surface,  and 
intermingled  with  ambulacral  pieces.  This  specimen  was  illustrated  by 
Neumayr  on  page  473,  from  our  figure  in  Part  III  of  the  Revision,  and  he 
must  have  taken  the  irregular  inner  pieces  for  the  orals,  for  only  in  this 
way  can  we  understand  the  explanatory  remarks  accompanying  the  figure. 
He  says  :  "  Wachsmuth  and  Springer  figure  a  most  remarkable  example  of 
Ci/athocrinns  muUibrachiatus,  in  which,  as  they  .show,  the  orals  (summit  plates) 
are  in  process  of  resorption,  and  in  part  replaced  by  small  plates."  In 
C.  alulaccns  also,  he  took  the  inner  plates,  which  in  this  species  are  un- 
usually large  and  regular,  for  the  orals,  and  for  the  homologues  of  the 
outer  plates  of  C.  malvacetts*  0.  Gilcsi,  and  C.  hrevisaeculm. 

"  Neumayr  gave  (Stamme  des  Tliierreiclics,  p.  450),  after  Meek  and  Wortlicn,  two  figures  of  tlie  ven- 
tral surface  of  this  species:  Fig.  2,  representing  the  "  Kelclideckc  " ;  Fig.  3,  "Dicselbc,  uacli  Entfernung 
dcr  Dcckiiliittclicn."  The  former  has  five  largo  intcrradial  plates,  with  a  vacant  space  in  the  centre,  mucli 
larger  than  tliat  of  C.  Gilesi,  and  the  ambulacral  grooves  are  exposed.  In  the  latter  tlie  centre  is  closed  by 
seven  plates,  almost  as  large,  and  as  regular  in  their  arrangement  (a  central  ))late  surrounded  by  six  proxi. 
mals),  as  in  C.  alulnceu-i.  That  he  took  these  plates,  contrary  to  those  of  C  alufmrus,  for  covering  pieces, 
extensions  from  the  ambulacra,  and  not  for  orals  and  central  plate,  is  clearly  indicated  by  the  explanation  of 

the  figures. 

13 


ili 


i 


I 


i 


98 


THE  CRIXOIDEA  CAMERATA  OF  NORTH  AMERICA. 


I  fir 

nil 


(   i'', 

m 


m 


mi 

III 


Neumayr's  interpretation  of  the  plates  meets  with  serious  diiricuitics. 
There  are  in  C^a/hocriitus  uniloubteilly  two  sets  of  plates ;  the  one  occupy- 
ing the  cent»'e  of  the  disk,  and  covering  completely  mouth  and  peristome, 
without  grooves,  and  with  the  ambulacra  subtegminal;  the  other  occupying 
the  outer  margins  of  the  disk,  grooved,  the  ambulacra  tcgminal,  and  covered 
over  by  perisome  which  extends  inward  and  closes  the  mouth.  He  under- 
took to  explain  these  difliculties  by  palasontological  development,  but  over- 
looked the  fact  that  in  the  ontogeny  of  recent  Crinoids  the  perisome  is 
introduced  above  the  radials,  and  between  the  orals,  and  that  the  latter  are 
carried  relatively  inward.  The  same  mode  of  development  we  find  in  the 
phylogony  of  fossil  forms;  the  orals,  with  the  introduction  of  interradial 
plates,  are  moved  to  the  centre  of  the  disk,  and  either  cover  the  mouth 
or  mmcd'uttclij  siirrouiul  it.  That  is  the  caso  in  the  Camerata  and  the  Articu- 
late Ichthyocrinida?,  and  there  is  no  reason  to  doubt  that  it  is  the  same  way 
in  the  Cyathocrinidiv.  In  the  Larviformia,  however,  in  M'hich  there  is  no 
perisome,  the  orals  rest  against  the  radiiils,  but  also  cover  the  mouth,  as 
they  do  in  the  Pentacrinoid  larva. 

We  believe  with  Neumayr  that  the  differentiations  among  the  species 
which  we  have  noticed  in  the  disk  of  Ci/athocrimis  are  modifications  due  to 
palaiontological  development.  It  seems  to  us  that  the  orals  throughout  this 
genus  are  more  or  less  in  a  state  of  resorption,  more  advanced  in  one  species 
than  in  another,  and  even  varying  in  degree  in  the  same  species.  From  this 
we  conclude  that  the  Silurian  C.  aluUiccus,  in  which  the  orals  are  almost  or 
wholly  intact,  represents  the  more  primitive  form  of  the  genus,  and  C.  iiialva- 
cetis,  etc.,  a  later  stage ;  and  that  Empirncrimts,  in  which  the  orals  are  appar- 
ently completely  removed,  and  the  ambulacra  thereby  brought  into  view 
upon  the  disk,  represents  a  more  advanced  stage  than  either  species  of 
Cyuthocrmus. 

For  proof  that  a  resorption  took  place  in  the  same  species,  we  refer  to  the 
specimen  of  C  alutacnis,  Fig.  7,  which  differs  essentially  from  Fig.  G.  It  is 
also  proved  by  numerous  specimens  in  our  collection,*  which  show  distinctly 
that  the  orals  are  proportionally  larger,  and  more  regular  in  their  arrange- 
ment in  young  specimens  than  in  the  adult.  In  one  of  the  specimens,  not 
larger  than  a  good-sized  pea,  they  occupy  fully  two-thirds  of  the  disk,  being 


•  Wo  have  from  sixty  to  seventy  specimens  in  most  excellent  preservation,  represeiitinR  five  species,  in 
which  we  exposed  tlie  disk  by  removing  tlie  arms.  Jlost  of  them  came  from  Indian  ereck,  Ind.  (Keokuk 
group),  though  some  arc  from  Burlington,  and  a  few  from  Crawfordsville. 


MORPHOLOGICAL  PAllT. 


09 


thus  considerably  larger  than  the  plates  occupying  its  outer  niaryins,  which 
arc  also  exposed  in  that  specimen. 

We  thus  find  persistent  among  Palaeozoic  Crinoids  all  the  phases  through 
which  the  orals  pass  in  their  individual  growth  in  recent  forms,  from  the 
early  Pentacrinoid  larva  oi  Anh'duii  to  the  adult  IIi/omnuH  (Plate  III,  Fig.  10) 
in  which  they  are  very  large,  and  Calumocriintu  *  in  which  they  lire  extremely 
small ;  and  we  find  the  plates  in  process  of  resorption  and  entirely  removeil 
from  the  system. 

We  further  find  that  the  orals  in  all  Crinoids,  recent  and  fossil,  v.hen 
represented,  occupy  the  centre  of  the  disk,  immediately  surrounding  the 
mouth  or  covering  it,  and  that  the  orals  of  the  earlier  forms  differ  from  tliose 
of  the  recent  only  in  their  asymmetrical  arrangement,  caused  by  the  greater 
rigidity  and  more  extensive  development  of  the  anal  structures. 


I 


n 


B.     Mouth  and  Amhdacra. 

The  presence  of  a  single  aperture  in  the  disk  of  Palaeozoic  Crinoids 
induced  the  earlier  writers  to  suppose  that  this  opening,  although  interradi- 
ally  disposed,  served  both  as  mouth  and  vent.  Later  ob.servations,  and 
a  better  knowledge  of  the  general  structure  of  recent  Crinoids,  their  mode 
of  feeding  and  the  nature  of  their  food,  have  shown  conclusively  that  this 
opening  is  not  the  mouth,  but  the  anus,  and  that  the  mouth  in  most  PaUvo- 
zoic  forms  was  subtegminal. 

The  mouth  of  all  Crinoids  is  directed  upwards,  being  placed  in  the  centre 
of  radiation,  but  does  not  in  all  of  them  occupy  the  centre  of  figure.  It  is 
very  frequently  subcentral,  and  may  be  altogether  excentric.  The  latter  is 
the  case  in  the  asymmetrical  genus  Acllnomcim,  and  to  some  extent  in  all 
Fistulata,  in  which  the  posterior  side  of  the  disk  is  extended  into  a  large 
tubular  or  sac-like  prolongation.  It  is  subcentral  in  most  of  the  Camerata, 
and  central  in  all  known  recent  forms,  Adinometra  excepted. 

The  ambulacra  occupy  the  grooves  along  the  ventral  side  of  the  arms, 
and  extend  from  the  tips  of  the  pinnules  to  the  mouth.  Their  proximal 
ends  are  either  exposed  upon  the  disk,  or  covered  wholly  or  in  part  by 
plates  of  the  tegmen.  Entering  the  mouth  there  are  five  main  trunks, 
which  ramify  so  as  to  give  a  branch  to  every  arm  and  pinnule.  The  upper 
face  of  the  ambulacra  is  occupied  by  the  food  grooves,  which  are  roofed  over 

•  A.  Agassiz,  ^Icmoirs  Mus.  Comp.  Zool.,  Vol.  XVII,  Plate  0,  Figs.  1  aud  2. 


' 


I 


100 


THE  CBIXOIDKA  CAMKRATA  OF   NORTH   AMERICA. 


Ifc 


■1; 

It 


\)y  the  covering  plates,  and  fiecinently  bonleruil  by  small  side  pieces ;  the 
I'ormer  arnuiguil  alternately  with  each  other  and  with  the  side  pieces.  In 
the  living  uniinal  the  food  grooves  are  lined  by  cilia,  whith  are  kept  in  a 
continual  vibratory  motion  ,so  as  to  produce  ciu'rents  of  water,  by  nieiiiis 
of  which  any  particles  of  food  that  hapjjen  to  fall  upon  the  grooves  are 
transmitted  toward  the  mouth.  Beneath  the  food  groove  lies  a  nervous 
band,  and  beneath  that  a  blood  ve.s.sel,  which  in  turn  is  followed  by  the 
genital  canal,  and  this  by  the  subtentaculur  canal ;  the  genital  canal,  which 
is  quite  small,  occupying  only  the  median  portions.  The  subtentacular 
canal,  also  known  as  the  ambulacral  canal  proper,  from  which  branches  are 
given  off  to  the  tentacles,  communicates  with  the  annular  ves.sel  situated  in 
the  lip  around  the  mouth.  Beneath  the  ambulacra  is  the  nxial  canal.* 
which  occupies  the  bottom  of  the  arm  grooves,  frequently  piercing  the  body 
of  the  plates.  This  canal  is  connected  with  the  chambered  organ  at  the 
lower  part  of  the  dor.sal  cup,  and  contains  the  axial  cords,  which,  as  now 
generally  admitted,  control  the  movements  of  the  arms  and  pinnules ;  while 
the  nervous  apparatus  beneath  the  food  grooves  bus  no  connection  with 
the  muscles,  and  no  inlluence  upon  the  movementh  of  the  skeleton. 

The  ambvdacra  of  fossil  Crinoids  are  rarely  observed,  and  their  presence 
is  usually  only  indicated  by  the  open  grooves  within  the  arm  skeleton.  In 
some  cases,  however,  the  side  and  covering  pieces  of  the  di.sk,  and  occasionally 
those  upon  the  arms,  are  preserved. 

In  all  recent  Crinoids  the  covering  pieces  are  movable  from  the  tips  of 
the  pinnules  to  where  they  enter  the  mouth,  but  they  are  rigid  upon  the  disk 
in  Palivozoic  species,  with  perhaps  a  few  exceptions.  In  the  Camerata,  and 
especially  among  the  Platycrinidae,  they  are  often  heavier  and  larger  than 
the  interandjulacral  plates;  while  in  other  groups,  and  chiefly  among  Silurian 
forms  (Plate  III.  Fig.  11),  they  are  quite  small.  The  larger  the  plates,  the 
more  irregular  they  arc  in  their  arrangement,  and  the  sm.aller  the  most 
regular.  It  is  also  noteworthj'  that  the  andjulacra  may  be  tegminal  or  sub- 
tegminal  in  the  same  genus.  Those  of  the  Platycrinidfe,  as  a  rule,  are  tegmi- 
nal, those  of  the  Actinocrinidas  generally  subtegminal ;  but  also  the  opposite 
is  the  ca.se  in  genera  of  both  groups. 

There  is  considerable  variability  in  the  extent  to  which  the  ambulacra 
are  exposed  upon  the  surface.  In  the  Camerata  they  never  extend  out  to 
the  centre  of  the  tegmen,  their  proximal  ends  being  always  hidden  by  the 

•  This  canal  is  also  known  as  the  "  Dorsal "  canal,  and  as  tlic  "  Cocliac  "  canal.  • 


ifi 


5IORPIIOL00ICAL  PART. 


101 


oraln,  iind  wlion  these  nre  wantinj?,  by  some  of  the  intorftmbiilncrul  plates ; 
or  hy  both,  in  which  cnse  only  mnall  portions  of  them  are  seen  near  the  arm 
bases.  In  the  Fistulata,  the  disk  ambulacra  are  either  altogether  tegminal. 
or  their  ends  are  covered  by  the  orals.  In  the  Ichthyoerinida'.  so  far  as 
observed,  and  in  recent  Crinoids,  they  extend  to  the  mouth,  whether  onds 
are  represented  or  not;  but  while  in  Tn.romuiis  (Plate  III.  Fig.  11)  they 
are  in  the  same  plane  with  the  orals,  and  are  attached  to  them  laterally, 
in  recent  forms,  in  which  the  orals  are  opened  out.  they  are  deeply  in- 
serted between  the  interaml)ulacra!  plates,  so  as  to  be  almost  obscured. 

The  disk  ambulacra  of  the  Camerata,  if  tegminal,  form  a  component  part 
of  the  tegmen,  being  suturally  connected  with  the  intoramltulacral  plates,  and 
with  the  orals.  In  the  Cyathocrinida;,  however,  and  probably  in  other  Fis- 
tulata, they  rest  upon  largo  interradial  plates,  and  between  the  small  margi- 
nal pieces  which  cover  the  surface  of  the  latter.  In  the  lehthyocrinidie  and 
recent  Crinoids,  they  are  separated  by  minute  interamltulacral  pieces. 

The  ambulacra  of  the  Catnerata  rarely  have  any  side  pieces,  these  being 
represented,  so  far  as  known,  only  in  Mfi/ixfapriiiiis  (Plate  XL\'1I.  Figs. 
7  and  8  a,  b),  in  Cdctocrinm  (Plate  LVIII.  Fig.s.  7  n,  1>),  and  in  L'/riocrhiiis 
(Plate  XI.  Fig.  4  c).  They  are  present,  however,  in  most  Fistulata.  but 
absent  in  the  Larviformia. 

That  the  covering  pieces  in  the  disk  of  C/jfif/iocrinns,  as  suggested  by 
several  writers,  were  movable,  so  as  to  expo.se  the  food  grooves,  seems  to 
us  improbable,  although  there  is  no  serious  objection  to  it  from  a  morpholo- 
gical point  of  view ;  but  the  perfect  preservation  of  the  plates  in  so  many  of 
our  specimens  seems  rather  to  indicate  that  they  were  rigid.  They  may 
have  boen  movable  in  groups  in  which  the  mouth  is  opened  out,  but  where 
it  is  closed  they  were  probaljly  rigid  throughout  the  disk. 

In  some  of  the  Camerata  in  which  the  primary  arms  are  d  veloped  into 
tubular  appendages,  and  secondaiy  arms  are  given  off  at  the  sides,  as  in 
Eiichitlmriiws  (Plate  LXXIII.  Fig.  .3,  Plate  LXXIV.  Fig.  4),  and  Stcyamcriiim 
(Plate  LXI.  Fig.  1  c),  the  covering  plates  of  the  main  arms  are  almost  rigid 
to  the  full  length  of  the  ray,  and  only  those  of  the  side  arms  and  their  pin- 
nules were  movable.  But  it  must  be  remembered  that  these  appendages  are 
practically  extensions  of  the  calyx. 

Subtegminal  ambulacra,  so  far  as  we  know,  occur  only  among  the 
Camerata  and  Larviformia.  In  the  former  there  are  frequentlj-  along  the 
inner  floor      tbe  tegmen  deep  grooves  or  ducts,  which  are  formed  either  by 


V. 
»  s 


n 


[■\ 


102 


THK  CHIXOIDEA  CAMKUATA  OF   NOIITII  AMKUICA. 


a  folding  of  the  tost  or  a  tliickeniiiy  of  thu  plates,  uml  wliicli  procecil  from 
tlic  inukllo  of  the  lloor  to  the  iuin  openings  (IMtite  V.  Figs.  13,  1-1,  15,  1(5, 
and  17).  Within  these  grooves  me  lodged  the  unibulacni,  whiuh  me  repre- 
sented by  n  skeleton  of  riuliiiting  tubes,  following  the  inner  surriice  of  the 
di.sk  (Plate  V.  Figs.  1  and  10;  I'late  IV.  Fig.  S).  Tiie  tubes  are  composed 
of  four  rows  of  plates,  two  below  and  two  ul)ove,  both  alternately  arranged, 
the  former  probably  representing  subanibulaeral  pieces,  the  latter  covering 
plates.  The  skeleton  has  never  been  found  completely  preserved,  but 
enough  is  shown  to  indicate  that  the  tubes  do  not  extend  out  to  the  centre, 
but  meet  in  an  annular  ve8.sel  surrounding  the  mouth.  This  at  least  seems 
to  have  been  the  structure  of  Mucroirintis  rcniati/idniis,  in  which  an  almost 
circular  vessel  has  been  observed  beneath  the  centre  of  the  disk  at  some 
distance  from  the  inner  lloor  (Plate  V.  Fig.  8).  No  anibulacral  tubes  are 
attached  to  it  in  the  specimen,  but  it  lia.s  five  openings  in  a  radial  direction, 
which  evidently  communicated  with  the  ambulacral  vessels.  The  ring  is 
rather  large,  and  is  placed  around  the  contracted  upper  part  of  the  con- 
voluted organ,  which  is  also  preserved  in  the  specimen. 

Tiie  direction  of  the  ambulacral  tubes  and  tiieir  branching  is  well 
observed  in  natural  casts,  in  which,  after  the  calcareous  parts  arc  removed, 
the  ducts  of  the  tubes  are  represented  by  filiform  elevations  upon  tlie 
surface  (Plate  IV.  Figs.  1,  2,  3,  4,  5),  sometimes  even  showing  impressions 
of  ambulacral  pieces.  It  also  appears  from  the.se  casts  that  the  ambulacra 
in  some  cases  rested  directly  against  the  tegmen,  and  in  others  lay  at  a  dis- 
tance from  it,  only  touching  the  test  at  the  arm  bases.  Tlic  latter  was 
undoubtedly  the  case  in  the  interesting  specimen  of  riali/crinm  (Plate  IV. 
Fig.  G),  in  which  the  ambulacral  plates  are  clearly  marked  near  the  margins 
of  the  disk,  while  no  traces  are  found  of  their  inner  portions.  If  the  ambu- 
lacra had  touched  the  inner  floor,  the  delicate  markings  of  the  disk  plates 
would  not  be  in  sight,  but  instead  of  them  traces  of  the  tubes  would 
appear  upon  the  surface.  This  is  corroborated  by  the  cast  of  Dor/jcriiiKS 
(Plate  IV.  Fig.  5),  in  which  the  ambulacra  are  visible  to  the  outer  edges  of 
the  orals,  but  disappear  underneath  them.  Also  in  the  beautiful  specimen 
of  Cacfocrinus  proboscidulis  (Plate  V.  Fig.  10),  where  the  tubes  are  removed 
from  the  floor,*  and  in  Teleiocrinus  (Plate  IV.  Fig.  1),  and  in  Cacfocrinus  glniis 

*  NiMimnvr,  'wlio  knew  this  specimen  from  Meek  and  Wortlien's  (Igurc,  expressed  the  opinion  tlint  n 
settling  of  tlie  tubes  probal)ly  took  pinee  after  tlic  dcnlli  of  the  nnimai.  lie  based  tliis  ojiinion  upon  tlie 
structure  of  the  casts,  in  which  he  supposed  the  ambulacra  were  always  exposed  at  the  surface,  which,  as  we 
have  stated,  is  by  no  means  the  case. 


MORPriOl.OniCAL  PART. 


103 


(Plato  IV.  Fig.  8).  Tliiit  they  wore  attnclietl  to  the  tcgmen  in  iniiny  of  these 
CrinoidH,  ntid  prol)iiI)ly  in  the  iniijority  of  them,  in  also  Muygcuteil  hy  the 
premMicc  of  the  Mo-called  radial  dome  plates. 

The  name  "radial  dome  plate.s"  was  given  by  iih  to  a  Met  of  large  plafe,>t 
in  the  tcgmon,  radially  dispo.sed,  and  oeciipying  the  regions  lietween  the 
orals  and  tho  arm  bases.  The  plates  arc  generally  larger  than  the  surronnd- 
ing  ones,  ami  qnite  froqnently  nodose.  They  wore  rcgar<led  by  ns,  and  also 
by  Dr.  P.  II.  Carpenter,  nntil  iinite  recently,  as  the  aelinal  representatives  of 
the  radials,  but  later  investigations  prove  the}'  are  highly  dilTerentiated  cov- 
ering  piocos.  The  plates  are  either  followed  by  two  series  of  regular  cover- 
ing piece.s,  nnd  pass  out  from  between  the  angles  of  the  orals,  or  they  are  to 
a  certain  extent  isolated,  surrounded  by  other  plates,  and  snccoeded  by  simi- 
lar plates  of  higher  rank.  The  former  is  the  case  in  most  of  the  Platycrinida> 
and  Ilexaerinida',  the  latter  among  the  Actinocrinidio  and  Khodocrinida'  with 
subtegminal  ambulacra.  That  the  plates  in  the  former  case  are  simply  cover- 
ing pieces,  is  readily  perceived  by  examining  those  species  in  which  the 
plates  are  but  little  disturbed.  Taking  Pl<if//irini(s  and  Dlchovrinus,  wo  find 
in  both  genera  certain  species  in  which  two  series  of  small,  almo  it  regularly 
arranged,  altcrnaiing  pieces  pass  out  from  the  orals  to  the  arms.  Such  is  the 
case  in  Plid/jcriiim  Ki/unnrtrlrm  (Plato  LXIX.  Figs.  1  h,  c),  in  Dii/iocrinns  po///- 
ihetylHS  (Plate  LXXVII.  Fig.  1  h),  and  in  1).  /,<c/irm>ms  (Plate  LXXVII. 
Fig.  2  c).  Similar  plates  under  similar  conditions  also  occur  in  the  Silurian 
Mtrmipiocrltms  (Plate  VIII.  Fig.  15,  and  Plate  LXXV.  Figs.  IGA  and  18),  and 
among  Silurian  genera  of  other  groups.  There  are  no  largo  plates  next  to 
the  orals,  and  hence  no  radial  dome  plates,  unless  thoy  are  represented  l)y 
the  small  pro.ximal  plates.  From  this  struciuro  to  that  of  r/<ih/rn'iiiis  dis- 
coidem  (Plate  LXVI.  Fig.  10  b),  and  P.  ILdli  (Plato  LXXII.  Fig.  7  "),  there 
is  but  a  short  step.  The  plates  in  question  are  comparatively  larger,  espe- 
cially tho  proximal  ones,  and  arranged  alternately,  although  not  so  regularly 
as  in  tho  former  species.  In  PUdijcn'mis  hitrli»f/foneusi,i,  however  (Plate  LXIX. 
Fig.  3  f),  and  P.  YandcIU  (Plate  LXVIII.  Fig.  3  c),  there  is  generally  a  large 
plate  followed  by  smaller  ones,  and  the  alternate  arrangement  of  the  plates 
actually  commences  at  the  arm  bases.  If  wo  had  only  tho  latter  species,  we 
might  perhaps  be  justified  in  regarding  those  proximal  plates  as  independent 
structures ;  but  comparing  them  with  those  of  other  species  in  which  the 
arrangement  is  more  regular,  it  becomes  evident  that  they  are  all  nothing 


n 


I 


'' 


104 


TIIF.  C'HINOIDKA   CAMKUATA   Ol"   NOUTII   AMI.IUCA. 


I)iit  covoriiig  i)ii;ci'>.  wliieli  gnulimlly  in  geological  time  cliungL'il  tlicir 
uluiractcr. 

Tho  "  indiiil  duiiiu  pliitcM"  uf  tlio  Actioiiucrinicliu  iiiid  nllicil  fonuH  mu 
gotu'i'iilly  liirgor  tlmii  niiy  ol' the  Miirroiiiuliiig  ijliitos,  often  iiodoMe,  ami  hoiiio- 
tiniuM  extended  into  long  HpincM.  Tlioy  uru  nut  ibllowcd  innncdiiilely  by 
covering  pieces,  um  already  wtated,  and  are  placed  at  some  distance  from 
tlio  orals,  —  occupying  in  the  Minipler  forni.s  with  bnt  two  arms  to  the  ray 
almost  till'  outer  margins  of  the  tegmen  {AjarievvtlniiK),  —  directly  owr  the 
point  at  which  the  bifurcation  of  the  ambulacra  takes  place.  When  there  are 
I'onr  arms  to  the  ray,  they  are  removed  relatively  further  inward,  and  are 
followed  by  two  similar  but  smaller  plates  of  higher  raid^.  But  when  there 
are  three  arms  to  the  ray,  there  is  only  one  Huch  plate,  which  is  directed  to 
the  side  where  the  bifurcation  is,  the  opposite  hide  of  the  plate  being  followed 
by  the  regular  covering  pieces  of  the  arms. 

From  this  structure  we  may  infer  that  the  so-called  radial  dome  plates 
with  sul)tegminal  ambulacra  are  axillaries,  and  if  they  represent,  as  we  have 
rea-^on  to  believe,  modified  covering  pieces,  that  they  are  the  plates  from 
which  the  ainljulacra  bifurcate.  In  this  view  it  is  quite  suggestive  that  the 
axillary  plates  of  the  ambulacra  are  frequently  protuberant.  In  Enclmlieri- 
iins  iiiilldirachialus  (Plate  LXXIII.  Fig.  1),  they  nre  nil  along  the  main  arms 
strongly  nodose,  and  if  tho  ambulacra  of  this  species  had  been  covered  by 
other  plates,  the  tips  of  the  axillaries  naturally  would  project  above  them 
and  be  exposed  upon  tho  disk.  In  this  way  the  radial  dome  plates  nniy  have 
originated,  so  that  afterwards  the  upper  portions  developed  to  larger  si/e,  and 
finally  become  independent  plates.  This  explanation  seems  to  us  most  prob- 
able, and  it  was  favorably  received  by  Carpenter. 

The  Paheontological  evidence  indicates  that  in  the  earlier  Caincrnta,  ns  in 
the  young  specimen  at  some  time,  the  ambulacra  were  exposed  ujjon  the 
disk.  In  most  of  the  Silurian  forms  they  took  part  in  the  tegmen,  and  their 
covering  plates,  as  a  rule,  were  more  regular  in  their  arrangement  than  in 
those  of  later  epochs.  In  the  Carboniferous,  with  the  exception  of  the 
Platycrinida),  Hexacrinidoo  and  Acrocrinidaj,  the  ambnlacra  are  almost 
exclusively  subtegminal,  and  the  whole  disk  assumes  that  extravagant 
form  which  led  at  one  time  to  the  belief  that  it  represented  an  entirely 
different  structure. 


Mom-llOlAMilCAl,   I'AItT. 


III.   siim'm:mi;ntaiiy  i'latks. 


106 


A.      The  Dii<(rit>iilioii  <>/  lliv  I'IkIik,  uml  llnlr  Itt'tnltimn  in  the  Di//'iirH/  Oronpi. 

Tho  jstippleiiuridil  iilati'M  coiiipiiNo  all  liiiu'stoin'  piiitirlL'M  Itctwccii  tlio 
ba^nls  and  (inil-''  and  iiiti'ivcnin^  l)ot\vei'n  tlio  lays  and  tlicii'  HulidiviNiotiH, 
They  iiro  <HviduJ  into  interradial,  intoiiixiliary,  and  anal  pliitcx.  The  ii)tRr> 
radial  plutt'x.  coiiipriNU  as  a  gcnuml  turiii  all  platoH  bctwueii  llu>  liii.><als  ami 
orals,  intonadially  disposed.  Sonu  of  tliom  aro  disfiiijruislnMl  at*  iiitiT- 
brachials,  otliors  as  inforaiiibnlacrals.  Tho  iiitcrhrachials  aro  coni'iiod  to 
tlio  dorsal  cup,  Tho  iutoniiiiliiilacrals  occupy  tho  spaces  hetweoii  tho  am- 
bulacra. Tho  intera.xillarios,  consisting  of  the  intonlisticlials  and  intor- 
palmars,  aro  locatod  within  the  axils  of  tho  Hocond,  third,  and  Miicceoding 
onlors  of  brachials  respo(!tively.  Tho  anal  plates  aro  restricted  to  tho 
poitorior  interradiiis  supporting  tho  anal  tube.  Another  system  of  small 
plates  occurs  in  tho  Acrocriniilie,  where  they  form  a  wide  bell  inter- 
mediato  between   the  basals  and   radials. 

In  nearly  idl  Crinoids,  recent  and  fossil,  in  which  tho  free  arms  do  not 
start  directly  I'nmi  the  radials,  the  lower  arm  joints  are  incor|)orated  into  tho 
calyx,  either  by  soft  tissues  or  by  means  of  plates.  The  latter  are  exceed- 
ingly variable  in  form  and  character,  being  in  some  groups  well  developed 
and  rigid  ;  while  in  others  they  aro  irregular,  ill-formed  pieci's,  or  mere  liine- 
Htono  particles,  resting  within  soft  tissues.  The  gieat  variation  observable  in 
tho  structure  of  the  plates  among  dillerent  groups  led  to  the  belief  that  tho 
rigid  and  regularly  arranged  i)ieces,  which  are  so  characteristic  of  the  Came- 
rata,  did  not  belong  to  the  same  system  of  jdates  as  the  irregular,  small 
pieces  which  unite  tho  rays  of  recent  Crinoids ;  and  Dr.  P.  II.  Carpenter 
applied  to  the  former  the  term  "calyx"  interradials,  as  opposed  to  tho 
interradial  plates  of  the  "disk." 

A  somewhat  similar  distinction  was  made  respecting  the  plates  which  form 
the  ventral  pavement.  The  heavy,  rigid  pieces  of  Palaeozoic  forms  were 
called  "  vault "  plates ;  and  the  small,  irregular  pieces  of  later  and  recent 
Crinoids,  "perLsomic"  or  "disk"  plates.  The  term  "vault"  was  generally 
applied  in  ca.ses  where  the  month  and  food  grooves  ore  permanently  closed, 
and  "  disk,"  where  the  mouth  and  food  grooves  aro  open. 

In  the  Camerata,  tho  interbrachials  are  nearly  always  arranged  on  a 
definite  plan,  and  are  stout,  large,  and  united  by  close  suture,  making  the 

14 


ill 


li 


^1 


106 


THE  CRIXOIDEA  tAMERATA  OF  NORTH  AMERICA. 


whole  test,  to  the  bases  of  the  free  arms,  extremely  rigid.  The  interbruehial 
plates  of  the  regular  sides  generally  coinmeiice  with  one  plate,  which  in  most 
families  rests  upon  the  radials  and  between  the  costals.  It  is  usually  fol- 
lowed by  two  in  the  second  row,  and  two,  tliree,  or  four,  according  to  spe- 
cies, in  any  succeeding  ranges  there  may  be.  The  posterior  interradius  is 
fre(iuently  wider,  and  divided  vertically  into  two  halves  by  a  continuous 
or  interrupted  series  of  anal  plates  ;  but  it  may  be  constructed  like  the  other 
four.  In  the  Platycrinida3  and  IIe.\acrinida3  the  first  row  consists  of  three 
pieces,  which  are  for  the  most  part  neither  entirely  interbrachial  nor  entirely 
interambulacral.  In  the  Rhodocrinidaa  the  first  plate  interradially  disposed 
goes  down  to  the  basals,  thus  separating  the  rays  to  their  full  length.  This 
first  plate  is  therefore  not  strictly  interbrachial  in  po.-'ition,  as  it  lies  below 
the  horizon  of  the  lowest  brachials  ;  nevertheless  it  unquestionably  belongs 
to  the  same  system  of  supplementary  plates,  which  in  this  group  extend 
down  to  a  position  between  the  radials.  There  is  some  variation  in  the 
extent  to  which  the  radials  are  parted  by  these  intervening  plates.  In  some 
species  of  the  Ehodocrinida?,  exceptionally,  the  radials  are  only  separated  to 
half  their  length,  the  variation  occurring  among  different  specimens  of  the 
same  species,  and  even  in  different  areas  of  the  same  specimen.  We  find  it 
convenient  to  call  these  plates  interposed  between  the  radials  "  first  interra- 
dials"  where  it  will  avoid  circumlocution.  The  interbrachial  and  interaxillary 
plates  of  the  Reteocrinida3,  contrary  to  those  of  all  other  Camerata  are  in- 
formed, and  irregularly  arranged. 

The  interradial  plates  occupying  the  ventral  side  of  the  calyx  are  as  rigid 
as  those  of  the  dorsal  side,  but  are  as  a  rule  less  regularly  arranged.  They 
either  extend  up  to  the  orals,  or,  when  these  are  not  represented,  and  the 
ambulacra  are  subtegminal,  they  cover  the  whole  tegmen,  leaving  no  opening 
except  the  anns. 

At  the  inner  floor  of  the  tegmen,  we  find  in  most  of  the  Actinocrinido3 
and  Batocrinidoe  shallow  grooves  or  open  galleries,  which  are  well  shown  by 
the  natural  casts  figured  on  Plate  IV.  Figs.  1,  2,  4,  5,  6,  and  7,  in  which  they 
are  represented  by  the  elevations.  These  galleries  pass  out  from  near  the 
centre  to  the  arm  bases,  and  lodge  the  ambulacral  tubes.  Alongside  of  them, 
and  sometimes  covering  them,  there  is  frequently  in  both  families  —  but,  so 
far  as  observed,  only  in  certain  genera  —  what  appears  to  be  a  second  integu- 
ment (Plate  V.  Figs.  13,  15,  10,  and  17),  lying  parallel  to  the  inner  floor, 
which  was  formerly  supposed  to  represent  the  ventral  disk.     The  outer 


MORPHOLOGICAL  PART. 


107 


integument  was  regarded  as  a  structure  sui  ffcneris,  to  which  the  term  "vault" 
was  applied.  The  inner  integument  appears  at  first  sight  as  if  composed  of 
independent,  ill-foruied  pieces ;  but  ou  closer  inspection  it  is  found  that 
these  so-called  plates  are  extensions  from  the  plates  above,  and  continuous 
with  them.  Eu,;li  lower  part  is  connected  with  the  corresponding  upper  one 
by  small  surfaces  or  pillars,  and  joining  by  its  edges  with  other  like  plates, 
leaves  open  spaces  or  meshes  along  the  sides.  The  inner  portions  constitute 
a  kind  of  internal  lining  or  network,  extending  from  the  first  costals  and  first 
interbrachials  uninterruptedly  to  the  margins  of  the  orals.  In  some  speci- 
mens only  the  pillars  are  preserved,  the  lateral  extensions  of  the  plates  being 
wanting  ;  while  in  others  the  fioor  is  almost  entirely  smooth.  The  latter  is 
the  case  in  Cudocriims  probosckhtlts  (Plate  V.  Fig.  10) ;  while  in  Tekwcrimis 
rittlis  (Plate  V.  Fig.  16),  and  in  the  specimen  of  Dori/criims  {ibid.  Fig.  13),  the 
grooves  are  formed  into  well  defined  tunnels.  A  further  indication  that  there 
were  probably  two  integuments  in  some  of  the  Camerata  at  least,  seemed 
to  be  presented  by  the  ventral  structure  of  Siphomcrinus  armosiis  from  the 
Niagara  group  (Plate  XIX.  Figs.  .S  a,  b,  c).  Tliis  species,  so  well  known  from 
natural  casts,  has  a  largo,  trumpet-shaped,  subtegminal  anal  tube,  which 
crosses  the  mouth,  overlies  the  upper  ends  of  the  ambulacral  tubes,  and  is 
continued  subtcgminally  all  the  way  to  the  anterior  side  of  the  calyx,  even 
beyond  the  arm  regions,  whore  it  bends  outward.  The  case  is  best  illus- 
trated if  we  imagine  the  disk  of  a  recent  Crinoid,  witii  an  anal  tube  like 
that  of  Anlcdon  irffiilis  (Chall.  Rep,  on  the  Comat.,  Plate  XLVI.  Fig.  2), 
extended  all  the  way  out  to  the  arm  bases  of  the  anterior  ray,  and  covered 
by  a  vauit. 

It  seemed  hard  to  account  for  the  facts  presented  by  these  cases,  except  by 
the  presence  of  two  distinct  structures  covering  the  body  cavity ;  and  upon 
these  specimens  princip.ally  we  formed  the  opinion,  in  the  first  instance,  that 
the  Camerata  had  a  vault  and  a  subtegminal  di.sk,  and  that  the  vault  was 
a  structure  without  a  parallel  in  recent  Crinoids.  The  evidence  appeared 
to  be  conclusive  that  the  disk  was  subtegminal,  in  some  groups  at  least,  and 
this,  which  had  been  generally  acknowledged  by  leading  authors,  led  us  to 
believe  that  in  all  Camerata  the  disk  was  roofed  over  by  a  vault.  In  fact 
this  conclusion  seemed  to  be  corroborated  by  the  nature  of  the  plates,  Avhich, 
although  varying  considerably  in  size  and  number,  arc  arranged  in  all  these 
Crinoids  on  the  same  genernl  principle,  forming  in  all  of  them  a  compact, 
rigid  test,  with  the  mouth  and  food  grooves  perfectly  cIo.sed. 


108 


THE  CUINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


Carpenter  *  held  the  same  opinion  aa  to  the  vault  of  the  Actinocrinidoo. 
but  he  believed  that  the  "  vault"  of  a  Platycrinoid  "  corresponds  collectively 
to  the  orals,  interradials,  ambulacral  and  anainbulacral  plates  of  Ncocri- 
noids."  He  agreed  with  usf  that  the  calcareous  network  beneath  the 
"  vault "  of  an  Adimcrinua  "  corresponds  to  the  limestone  particles  on  the 
surface  of  the  internal  casts,  and  represents  the  anambulacral  plates  de- 
veloped in  the  perisome  of  recent  Crinoids."  He  also  admitted  "  the  com- 
plete resemblance  between  the  ventral  perisome  of  a  recent  Crinoid  and  the 
upper  surface  of  the  body  beneath  the  vault  of  an  Ac/inocriiius."  "  The  vault 
and  ventral  disk,"  he  said,  "  are  to  my  mind  entirely  distinct  structures." 
Of  the  vault,  he  said  further  (p.  172) :  "  I  believe  the  oral  or  actinal  system 
forming  the  vault  of  Ac/iiiocriniis  to  have  been  devcloiied  on  the  left  larval 
antenier,  in  exactly  the  same  way  as  the  apical  or  abactinal  system  is 
developed  on  the  right ;  but  the  oral  system,  instead  of  being  limited  to  five 
oral  plates,  as  in  Neocrinoids,  reached  a  very  extensive  development,  so  that 
in  its  conipletest  form  it  represents  such  a  parallel  to  the  apical  or  abactinal 
system  as  is  to  be  met  with  in  no  other  Crinoid."  From  these  passages  and 
others  in  the  Ciiallenger  Report,  it  appears  that  Carpenter,  as  well  as  we, 
supposed  that  in  Adlmicrinm  all  plates  of  the  calyx  up  to  the  arm  bases  were 
abactinal,  and  all  constituting  the  ventral  side  actinal ;  not  only  the  orals 
and  radial  dome  plates,  but  also  the  so-called  interradial  dome  plates  or 
interambulacral  pieces. 

We  retained  the  above  mentioned  opinion  until  1881;  but  afterwards 
our  views  were  materially  changed  respecting  the  interradial  dome  plates,:}: 
which  we  no  longer  regarded  as  actinal  structures,  but  took  to  be  con- 
tinuations of  the  interradial  plates  of  the  dorsal  cup,  and  as  fundamentally 
identical  with  them.  In  considering  the  matter  in  the  first  place,  we  had 
not  overlooked  the  fact  that  in  many  of  these  Crinoids,  throughout  different 
groups,  the  covering  plates  of  the  ambulacra  are  exposed  at  the  surface,  and 
as  such  would  form  a  part  of  the  "  vault." 

It  is  a  striking  fact,  in  the  Crinoids  as  elsewhere,  that  some  characteristics 
which  are  of  the  greatest  importance  from  a  morphological  point  of  view, 
prove  to  be  of  comparatively  little  value  for  classification.  This  is  the  case 
in  a  marked  degree  with  the  ambulacra  of  the  Platycrinidre  and  Actino- 
crinidae,  which  are  found  to  be  tegminal  and  also  subtegminal.    In  the  Platy- 

•  Clmll.  Rep.  Stalked  Crinoids,  pp.  172-180. 
t  Clmll.  Rep.  Stalked  Crinoids,  pp,  105,  IflO. 
X  Revision,  Part  III.  pp.  10-27  (Acad.  Nat.  Sci.  Pliila.,  pp.  238-249). 


MORPHOLOGICAL  PART. 


109 


/ 


crinidaB,  the  covering  pieces  are  generally  exposed  in  the  calyx,  while  in  the 
ActinocriniiltD  they  are  as  a  rule  hidden  from  view.  But  occasionolly  the 
opposite  is  the  case,  and  even  among  species  of  the  same  genus.  Actinocriims 
dellavis,  from  Belgium,  has  well  defined  covering  pieces  passing  out  from  the 
outer  edges  of  the  orals ;  while  almost  every  other  species  of  Ac/iimriiiits  has  in 
place  of  them  radial  dome  plates  of  the  first,  second,  and  third  order,  accord- 
ing to  the  number  of  bifurcations  in  the  calyx,  riiijselucnmis,  which  is  but  a 
modified  Adinocnnus,  has  in  some  species  orals  and  radial  dome  plates ;  while 
in  others  the  whole  ventral  surface  is  covered  with  small,  irregular  pieces. 
In  Adinocnnus  mnUinuUutm,  the  entire  tegnien  consists  of  only  a  few  unusu- 
ally large  interradial  plates,  which  interlock  with  those  of  the  dorsal  cup. 
But  the  interradials  in  most  of  the  Actinocrinidaa  pass  insensibly  into  the 
tegmen,  there  being  no  dividing  line  ;  while  in  Batocrinus  generally,  Init 
not  always,  the  interradials  of  the  dorsal  side  are  distinctly  separated  from 
those  of  the  ventral  side  by  the  arching  brachials,  —  a  structure  which  led  us 
at  first  to  suppose  that  the  plates  of  the  two  hemispheres  were  morphologi- 
Ctally  distinct. 

Similar  variations  occur  among  the  plates  of  the  tegmen  in  the  Platy- 
crinida)  and  Hexacrinidoe.  In  some  of  their  species  the  pavement  is  made  up 
entirely  of  massive  plates,  in  others  of  comparatively  thin  pieces ;  while  in 
still  others  the  ventral  surface  is  occupied  almost  exclusively  by  the  orals. 
In  both  groups  it  is  absolutely  impossible  to  draw  a  dividing  line  between 
interbrachials  and  interambulacrals.  The  plates  constituting  the  first  row, 
which  generally  consist  of  three  pieces,  are  peripheral  and  partly  interam- 
bulacral,  and  those  of  the  succeeding  rows  strictly  ventral.  The  plates  of  the 
second  and  higher  rows,  when  such  are  present,  interlock  with  those  of  the 
first  row,  like  the  interradial  plates  of  the  dorsal  cup  in  an  Acthiocrmis. 

The  condition  of  the  ventral  pavement  in  the  Mclocrinidte,  Ehodocrinida?, 
and  Tliysanocrinida)  is  similar  to  that  in  the  Actinocrinidoe.  Their  lower 
interbrachials  are  definitely  arranged,  and  there  is  no  line  of  demarkation 
between  the  plates  of  the  two  hemispheres,  except  that  produced  by  the 
arms,  which  pass  out  between  them.  In  the  Rotoocrinida),  as  in  most  of  the 
other  Silurian  Camerata,  the  whole  ventral  surface  is  covered  by  minute, 
irregular  pieces,  and  similar  plates,  with  a  few  somewhat  larger  ones  scattered 
among  them,  are  interposed  betweeti  the  rays  from  the  basals  up. 

It  seems  to  us  perfectly  clear  from  the  structure  that  all  interradial  and 
interaxillary  plates,  not  only  in  the  Camerata,  but  also  in  all  recent  and  fossil 


H 


110 


THE  CRIXOIDEA  CAMERATA  OF  NORTH   AMERICA. 


Criiioids,  where  they  exist,  are  auxiliary  pieces,  wiiich  increase  by  multipli- 
cation in  the  growing  animal,  filling  up  spaces  between  the  rays  and  their 
subdivisions.  They  increase  primarily  in  an  upward  direction,  but  partly  by 
intercalation,  secondary  plates  being  introduced  between  the  primary  ones. 
It  is  owing  to  the  intercalation  of  these  secondary  pieces  that  the  arrange- 
ment of  the  interradial  plates  in  the  upper  rows  is  less  regular  than  it  might 
otherwise  be.  In  the  simpler  forms  such  pieces  are  wanting,  or  only  occur 
close  to  the  arm  bases.  In  some  species,  however,  they  are  quite  numerous 
in  the  dorsal  cup,  as  well  as  in  the  tegmen,  and  in  the  Retcocrinida)  they 
constitute  the  greater  part  of  the  interradial  and  interaxillary  areas.  In  this 
family  small  pieces  continually  formed  in  large  numbers  in  the  growing 
Crinoid  along  the  margins  of  the  radials  and  brachials,  and  between  the 
primary  interradials,  so  as  to  isolate  these  from  their  fellows  and  from  the 
plates  of  the  r.ays  (Plate  IX.  Figs.  1  c,  be). 

The  interradial  plates,  as  already  stated,  are  continued  into  the  tegmen. 
This  may  be  readily  perceived  in  species  which  have  but  one  or  two  bifurca- 
tions in  the  calyx  ;  but  in  the  more  complex  forms  the  primary  structure  is 
frequently  obscured  by  the  introduction  of  secondary  pieces,  giving  the  im- 
pression that  the  plates  of  the  two  hemispheres  were  structures  morpholo- 
gically independent.  J^ooking  at  a  specimen  of  S/rofocrimis,  with  a  broad 
flanging  rim,  its  hundred  and  more  arms  crowded  around  it,  and  its  thousands 
of  minute  "vault"  plates,  growing  smaller  outward,  and  n^t  connected  with 
the  interradials  of  tlie  dorsal  side,  it  is  not  surprising  that  such  an  impression 
should  be  created. 

To  understand  the  structure  of  Siroiocriiiiis,  we  may  refer  to  that  of  the 
allied  genus  Sfc(/anocriiii(-s,  in  which  in  like  manner  the  arms  branch  oft'  alter- 
nately like  pinnules  from  the  two  main  divisions  of  the  rays;  but  while  in 
Strotocrinus  the  lower  parts  of  the  arms  are  incorporated  into  the  caly.x,  and 
form  a  continuous  rim  from  which  the  free  arms  start  off,  in  Sleganocr'iims 
the  two  divisions  of  the  rays,  bearing  their  small  alternate  arms,  remain  per- 
manently free,  and  extend  out  laterally  as  tubular  appendages  of  the  calyx. 
It  is  now  very  significant  to  find  that  in  Stcf/anocnmis  the  interradials  of  the 
dorsal  cup  meet  those  of  the  tegmen  in  such  a  manner  that  it  is  absolutely 
impossible  to  draw  a  line  between  the  plates  of  the  two  hemispheres  (>S'/<v/«»o. 
crimis  prnfagonm,  Plate  LXI.  Fig.  3  !>).  This  case  is  the  more  instructive, 
because  Sleganocrimis,  with  its  free  arms,  may  be  regarded  as  representing 
an  early  stage  in  the  developmental  history  of  Strotocrinus. 


MORPHOLOGICAL   PART. 


Ill 


A  structure  similar  to  that  of  Stegamcrinus  is  fomiJ  in  all  Camerata  in 
which  the  arms  are  free  from  the  tiistichals  up  ;  and  from  this  condition  all 
gradations  can  be  traced  to  the  complex  structure  of  Slrotocrlnm.  The  plates 
of  the  dorsal  cup  and  those  of  the  teginen  are  undoubtedly  parts  of  one  ele- 
ment ;  and  although  they  are  introduced  respectively  at  the  actinid  and 
abactinal  sides  of  the  calyx,  the  plates  of  the  one  side  cannot  be  regarded 
as  strictly  abactinal,  nor  those  of  the  other  as  actinal. 

Referring  again  to  Pktb/crinus,  Carpenter*  said  that  the  series  of  inter 
radials  found  in  the  peripheral  portion  of  the  vault  (tegmen) —  by  which  he 
meant  the  zone  between  the  proximal  dome  plates  (summit  plates)  in  the 
centre  and  the  calyx  interradials  (of  the  dorsal  cup)  —  belong  to  the  same  sys- 
tem of  interradial  plates  as  the  single  large  interradial  in  Q/athocriiius.  And  he 
continues:  "I  do  not  myself  think  that  the  vault  of  a  Plali/crinUc  was  exactly 
of  the  same  nature  as  that  of  an  Acliiiocrinite,  i.  e.  that  it  covered  in  the  whole 
of  the  visceral  mass  and  the  ambulacra  on  its  upper  surface.  For  if  the 
alternating  dome  plates  represent  the  covering  plates  of  recent  Crinoids,  as 
Wachsmuth  suggests,  then  all  the  periphery  of  the  dome,  outside  the  apical 
dome  plates  (orocentral  and  oral-i),  must  be  the  real  ventral  surface  of  the 
body,  and  not  a  tegmen  cuh/cis  as  in  Adinocnnus."  And  in  alluding  to  the  teg- 
men of  Mursiipiocrinus,  ho  said  :t  "  I  have  a  very  strong  impression  that  the 
so-called  vault  of  this  genus  is  really  the  strongly  plated  ventral  peris  "..e,  in 
the  centre  of  which  the  remains  of  the  orals  (apical  dome  p^ites)  are  j)erhaps 
to  be  found.  I  cannot  see  any  such  essential  difference  between  it  and  the 
plated  disk  of  Pcntacrimis  W/jvilk-thomsoni  or  of  many  Anteduns  (Plate  XVII. 
Fig.  6  ;  Plate  LV.)  as  would  lead  to  the  supposition  that  the  homologue  of 
the  latter  is  to  be  sought  for  beneath  the  vault  of  JfarsKpiocrhnis."  He  then 
alluded  to  the  closure  of  the  mouth,  and  to  the  covering  pieces  of  the  ambu- 
lacra, which  may  have  been  immovably  closed  down  over  the  food  grooves, 
saying:  "They  were  thus  converted  into  tunnels,  but  were  still 'external,'  in 
the  sense  of  not  being  covered  hy  a  '  tegmen,'  as  those  were  which  formed 
the  tubular  skeleton  beneath  the  vault  of  the  Actinocrinidne."  That  is  to 
say,  in  short :  Vault  and  disk  are  entirely  distinct  structures ;  and  the 
ventral  surface  of  one  Pakieocrinoid  represents  a  disk  because  the  am- 
bulacra are  external,  while  that  of  another  is  a  vault  because  they  are 
subtegminal. 

•  Clmll.  Rep.  Stalked  Crinoids,  p.  17S. 
t  Clmll.  Rep.  Stalked  Crinoids,  p.  170. 


112 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


We  hiive  already  pointed  out  tliat  the  covering  pieces  are  exposed  not 
only  in  the  Platycrinidic,  but  frequently  also  in  other  families  of  the  Canie- 
rata,  —  exceptionally  even  in  the  genus  Actiiwcriiius.  If  it  were  true  that  in 
Crinoids  in  which  the  disk  ambulacra  are  subtegminal,  the  integument  which 
covers  tiieni  is  a  "  mult,"  and,  on  the  contrary,  in  those  with  ambulacra  ex- 
posed,  or  "  exteriial,"  a  did;  it  seems  to  us  that  the  two  forms  should  be 
separated  as  distinct  orders,  and  it  would  follow  that  our  present  classi- 
fication of  the  Crinoids  is  arbritrary  and  worthless.  These  considerations 
produced  in  our  minds  a  firm  conviction  that  the  integument  in  both  cases 
must  represent  the  same  thing,  being  either  a  vault  or  a  disk,  —  the  plates 
either  all  vault  pieces  or  all  perisomic. 

In  some  species  of  Platijcvinm  the  ambulacra  make  their  appearance,  not 
at  the  margins  of  the  sunimit  plates,  but  at  some  point  intermediate  between 
tlio  orals  and  the  arm  bases,  from  beneath  the  upper  ring  of  the  interradial 
plates.  In  these  species,  applying  Carpenter's  interpretation,  the  lower  inter- 
radials  would  be  perisomic,  for  tliey  expose  the  ambulacra ;  but  the  upper 
ones  vault  plates,  because  they  do  not.  In  Plcrolocriims,  the  last  survivor  of 
the  Ilexacriuida),  a  very  higldy  differentiated  form,  the  tcgmen,  according  to 
Carpenter,*  '•  seems  to  have  had  a  closer  resemblance  to  that  of  Actinocnnus 
than  is  the  case  in  most  Platycriuida),  for  it  had  rjidial  dome  plates  of  tie 
first,  second,  and  even  occasionally  of  the  third  order."  In  other  Platycri- 
nida)  tiie  oral  system,  he  says,t  sooner  or  later  came  in  contact  with  the 
alternating  series  of  ambulacral  plates.  "  There  was  a  membranous  disk, 
the  radial  regions  of  which  were  travensed  by  the  ciliated  food  grooves 
beneath  the  ambulacral  skeleton  above  ;  while  the  interpalmar  regions  sup- 
ported the  interradial  plates  of  the  vault,"  Further  on  he  explains  that 
the  vault  of  the  Plat^crinidoc  is  not  a  true  vault,  or  tcgmen  cafz/cis,  like  that 
of  the  Actinocrinidtc,  but  corresponds  collectively  to  the  orals,  interradials, 
ambulacral  and  anambulncral  plates  of  Neocrinoids ;  contrary  to  the  vault 
of  Ac/iiiocrimis,  which  not  only  covers  in  the  food  grooves  themselves,  but 
also  their  skeleton  of  alternating  plates,  together  with  the  origin  of  the 
ambulacra  and  the   plated  interpalmar  areas  of  the  disk. 

We  never  imagined  that  Pkf//cn'iiits  had  anything  but  a  membranous 
disk,  which,  we  thought,  was  continued  underneath  the  interradial  plates 
all  the  way  to  the  arm  bases.  Neither  did  we  suppose  it  had  any  further 
plates   above  the  food  grooves  than  the   alternating  pieces  ;   nor   that   the 

•  Chall.  Rep.  Stalked  Crinoids,  p.  177.  t  Ib'^-.  PP  179-lSO. 


J 


MORPHOLOGICAL  PART. 


113 


latter  were  true  vault  plates,  aa  Carpenter  inferred  wc  did.  We  held  that 
while  in  the  vault  of  the  typical  Ac/mocnnua  the  iuterradial  dome  plates 
meet  over  the  ambulacra,  in  Pla/i/crimis  these  })lates  opened  out  so  as  to 
oxpo.se  the  covering  pieces,  and  that  the.se  were  gradually  incorporated 
into  the  vault.  In  a  typical  Platycrinoid,  the  covering  pieces  are  so 
modified  as  to  lose  almost  their  original  character,  being  as  large  and 
nearly  as  heavy  as  the  surrounding  plates,  and  they  are  united  with  one 
another,  as  well  as  with  the  latter,  by  close  suture.  In  some  of  tlie  later 
Platycrinidas  they  even  may  have  been  separated  from  the  food  grooves, 
for  in  the  internal  casts  they  lefl  no  impressions  ;  while  in  casta  of  Actino- 
criiius  from  the  same  localitie.",  and  in  casts  of  certain  Silurian  Plntycrinida?, 
tlie  outlines  of  the  ambulacra  are  generally  sharply  delineated  (Plate  LXXV. 
Fig.  14). 

Carpenter  probably  supposed  the  ventral  structure  of  the  Mclocrinidto 
and  RhodocrinidoB  to  be  in  the  same  condition  as  that  of  the  Actinocrinida) 
and  Platycrinidoc  respectively,  that  is,  a  disk  when  the  ambulacra  are  ex- 
posed, a  vault  when  they  are  concealed.  He  alluded  to  G/z/piocrimis  in 
connection  with  the  Reteocrinic'iaa  and  Ichthyocrinidoo,  in  all  of  which  the 
ventral  pavement  is  composed  of  an  immense  number  of  very  minute, 
irregularly  arranged  pieces.  In  the  Ichthyocrinida!  these  plates  are  trav- 
ersed by  regular  rows  of  alternating  pieces,  passing  out  from  the  oral  centre 
to  the  arms ;  in  the  two  other  families,  however,  such  alternating  plates, 
when  present  at  all  in  the  tegmen,  are  found  only  close  to  the  arm  bases. 
Carpenter  says  respecting  these  groups,*  "  I  venture  to  think  that  in  the  case 
of  Gli/ptocrimis,  Rctcocrinus,  Xcnocriniis,  and  also  of  the  Ichthyocrinida',  the  re- 
semblance to  the  Pentacrinidto,  Apiocrinidie,  iind  Comatuloe,  is  such  as  to 
leave  no  reasonable  doubt  that  the  so-called  vault  of  these  Palwocrinoids  is 
homologous  with  the  ventral  surface  of  the  body  in  the  Ncocrinoids."  This 
is  true  enough  as  to  Taxocnnus  and  Oni/chocrinus,  and  probably  the  Ichthyocri- 
nidne  generally,  in  which  mouth  and  food  grooves  are  exposed,  as  we  have 
found  out  from  actual  observation ;  but  in  the  case  of  Gl//ptocrimis  and  Ifcfco- 
crinus,  there  is  nothing  to  prove  it  beyond  a  superficial  resemblance  of  the 
plates.  Carpenter's  argument  lo,ses  much  of  its  force,  considering  that 
among  the  Actinocrinida)  within  the  same  genus  some  species  have  large 
plates,  others  very  small  ones,  and  the  evidence  seems  rather  to  prove 
that  either  these  plates  are  all  disk  plates,  or  none  of  them  are. 


n 


•  Chall.  Kep.  Stalk.  Crin.,  p.  185. 
15 


114 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


Essentially  tliffcrent  is  the  vcntrul  structiuc  of  the  Fistiilata,  which  have 
no  intonadiul  plates  in  the  dorsal  cup,  the  anal  piece  excepted ;  hut  those 
plates  are  extensively  developed  in  the  legmen.  Four  of  the  intcranibu- 
lacral  spaces  are  raised  but  little  above  the  level  of  the  arm  bases ;  while  the 
posterior  area  is  extended  abruptly  upward,  and  formed  into  a  sac  or  tube  of 
various  forms,  frequently  rising  beyond  the  tips  of  the  arms.  This  sac, 
which  may  be  regarded  as  a  greatly  extended  anal  area,  and  probably 
lodged  a  large  portion  of  the  visceral  mass,  must  not  be  confounded  with 
the  anal  tube  of  the  Camerata,  whicii  contains  simply  the  rectum.  Tiie 
sac  is  tubular,  bnlloon-shaped,  spiral,  or  club-shaped,  and  is  generally  com- 
posed of  longitudinal  rows  of  hexagonal  plates,  which  are  often  pitted  at 
their  sides,  or  perforated  by  pores.* 

The  structure  at  the  four  other  sides  of  the  disk  is  rarely  observed  ex- 
cept in  the  Cyathocrinidos,  in  which  it  was  probably  more  substantial  than  in 
the  other  families.  In  Cjuthocrinus  it  is  well  shown  in  our  figures  on  Plate 
III.  Figs.  1,  2,  3,  4,  C,  7,  8,  to  which  we  drew  attention  in  our  chapter  on 
the  orals.  There  are  six  plates,  interradially  disposed,  resting  against  the 
inflected  upper  edges  of  the  radials,  their  lateral  margins  covered  by  the 
ambulacra.  Four  of  them  are  larger,  cordiform,  and  of  equal  size ;  the  two 
others,  which  lie  at  the  posterior  side,  are  quite  narrow,  and  enclose  a  large 
perforated  plate  to  which  we  have  applied  the  term  mculrcporilc.  The  sur- 
faces of  the  four  larger  plates  in  perfect  specimens  are  roofed  over  by  num- 
erous delicate  pieces ;  while  the  perforated  plate  is  completely  exposed 
to  view. 

Ap  to  the  relations  of  these  plates  various  conflicting  views  have  been 
expressed.  Wachsinuth,  in  1877,  supposed  that  the  plates  collectively  con- 
stituted a  kind  of  consolidating  apparatu.s,  like  that  described  b^'  Roemer 
and  others  in  Cupressocrinus.  We  afterwards,  supposing  that  there  were  five 
plates,  suggested  that  they  were  structurally  identical  with  the  deltoids  of 
the  Blastoids,  which  at  that  time  were  regarded  as  homologous  with  the  orals 
of  the  Crinoids.      Similar  views  were  expressed  afterwards  by  Carpenter, 

•  Mr.  Batlier  is  of  the  opinion  that  the  ventral  sac  of  the  Fistulata  is  not  perforated,  hut  only  pitted 
(Geol.  Magazine,  >[ay,  1891,  p.  233,  and  elsewhere).  Tliis  may  he  true  as  to  Ci/athocriniix,  Eiispirocriinis, 
and  possibly  the  Ci/athnerinidir  generally,  in  wliieh  very  likely  the  madreporito  performed  tlie  fnneliiins  of  the 
tiibc-imres  ;  but  we  have  tlie  most  complete  evidence  that  among  the  Poteriocrinida;,  in  many  cases,  llie  jiores 
pass  tlirongli  tlie  test.  In  some  specimens  in  which  llie  lateral  edges  of  the  plates  were  exposed  ]>erfeelly 
free  from  the  matrix,  we  have  been  able  to  trace  the  duets  of  the  pores  to  the  full  depth  of  the  pl:ites.  They 
are  well  sliown  on  Plate  VII.  Figs.  2i,  5,  7,  8,  9.  Tiiat  tlie  openings  are  not  visible  iu  most  of  the  speei- 
meus  is  due  to  their  small  size  and  probably  also  to  the  mode  of  petrifaction. 


ii: 


MORPHOLOGICAL  PART. 


115 


Zittel,  and  Neumayr,  who  nil  regarded  the  plates  as  orals.  Plausibk-  ns  this 
theory  appeared  to  us  at  first,  it  involves  serious  morphological  diiriculties  ; 
and  in  1883,  on  discovering  that  the  plates  consist  of  seven  pieces  instead  of 
five,  we  abandoned  it,  in  which  we  were  1  >wed  by  Carpenter.  Since  then 
we  have  taken  the  plates  to  be  interradials,  although  with  some  hesitation, 
for  they  are  not  interbrachial,  nor,  strictly  speaking,  inter-ambiilacral,  but  in 
part  sub-ambulacral,  and  sub-tegminal.  In  tiieir  position  they  rosonible 
tlie  first  intcrradials  of  rialycrbuw,  but  the  ambulacra  of  that  genus  rest 
against  the  edges  of  the  plates,  and  only  the  covering  pieces  are  exposed. 
In  the  Cyathocrinidao,  not  only  the  ambulacral  jMcs,  but  also  the  ambulacral 
vessels  rest  upon  solid  plates,  and  the  small  marginal  plates  on  top  of  these 
plates  sustain  toward  the  side-  and  covering-pieces  the  same  r(>]ation  as  the 
interradial  plates  of  the  Platycrinida)  toward  their  covering  pieces. 

The  presence  of  three  plates  at  the  posterior  side,  as  against  one  at  the 
other  four,  would  seem  to  indicate  that  they  may  be  homologous  with  the 
first  row  of  interbrachials  of  the  Batocrinidoo ;  but  upon  closer  examination 
it  appears  that  the  two  structures  are  not  exactly  parallel.  We  have  no 
doubt  that  .ilso  in  Cyatliocrinus,  as  in  the  case  of  Batocrimts,  the  posterior 
plate  is  broken  up  into  two  pieces  by  the  middle  plate ;  but  this  plnte  in 
Cyatliocrinus  is  a  madreporite,  while  that  of  Batocri'mis  is  a  supplementary 
anal.  The  former  constitutes  the  xippcnnost  plate  of  the  posterior  inter- 
radius,  being  separated  from  the  first  anal  plate  by  the  full  length  and 
depth  of  the  sac;  the  plate  of  Batocrimts,  however,  which  rests  directly 
upon  the  anal,  represents  the  loivest  plate  of  the  area. 

Obscure  also  are  the  relations  of  the  small  marginal  plates,  which  in 
Cyatliocrinus  overlie  the  larger  ones,  and  which  occur  only  at  the  four  smaller 
sides  of  the  disk,  leaving  the  surface  of  the  madreporite  at  the  fifth  side  ex- 
posed to  view.  The  only  plausible  explanation  we  can  find  for  this  structure 
is  that  these  plates  represent  the  higher  disk  plates,  which  for  want  of  .space 
overlapped,  and  gradually  covered  the  larger  ones ;  while  those  of  the  pos- 
terior side,  instead  of  overlapping,  were  carried  upward,  and  formed  into  a 
sac  or  tube. 

The  large  interradial  plates  of  the  CyathocrinidoB  apparently  have  close 
affinities  with  the  deltoids  of  the  Blastoidea,  and  Carpenter  and  Bather* 
proposed  to  apply  also  to  the  plates  of  the  former  temporarily  the  term 
"  deltoids."     The  plates  of  both  groups  rest  upon  the  radials  and  support 

•  Ann.  and  Mag.  Nat.  Hist.,  1S92,  p.  U. 


116 


THE  CRINOIDEA   CASIKRATA  OF   NORTH   AMERICA. 


I' '. 


W: 


tlio  onils ;  but  while  those  of  the  Cyatliocrinidoe  enclose  a  madreporite,  those 
of  the  liliistuids  enclose  nn  iinal  piece.  The  conditions  nre  thus  not  cxnctly 
alike,  and  we  do  not  see  why  that  term  is  any  niore  appropriate  than  "  in- 
terradials"  —  a  term  which  has  the  advantage  of  being  more  general. 

In  the  Ilybocrinidiu  the  posterior  side  of  the  disk  is  less  elevated  than  in 
the  Cyathocrinida),  rising  but  little  above  the  level  of  the  other  four  sides. 
The  ambulacra  are  tegminal,  and  apparently  rest  upon  the  lateral  margins 
of  the  four  largo  interradial  plates.  There  arc  no  orals,  the  median  portions 
of  the  disk  being  occupied  by  large  covering  pieces. 

The  ventral  pavement  of  the  Anouialocrinidac,  which  we  examined  in 
a  fine  specimen  from  the  Museum  of  Comparative  Zoology,  difTers  essentially 
from  that  of  the  two  preceding  families.  It  consists  of  lather  large,  moder- 
ately thick,  irregular  pieces,  five  or  six  deep,  which  decrease  in  size  toward 
the  centre  and  cover  the  i)eristome ;  no  orals  being  distinguishable.  The 
outer  of  these  plates  rest  against  the  large  incurved  limbs  of  the  radials, 
forming  a  wide  and  deep  sinus  for  the  reception  of  the  ambulacra,  which  are 
on  a  lower  level  than  the  other  disk  plates,  and  in  the  Cambridge  specimen 
of  a  different  color,  and  thereby  readily  recognized. 

The  tegmen  of  the  Potcriocrinidto  has  never  been  foimd  in  perfect  pres- 
ervation. We  hoped  to  find  it  by  dissecting  a  number  of  finely  preserved 
specimens,  but  the  sacrifice  was  only  rewarded  by  finding  in  a  single  instance 
a  few  small,  scattered  plates;  from  which  we  conclude  that  the  covering  was 
of  very  fragile  construction.  The  form  and  size  of  their  ventral  sac  is  ex- 
tremely variable ;  extending  in  some  cases  beyond  the  tips  of  the  arms,  in 
others  consisting  of  merely  a  short  cone.  In  some  of  the  genera  i*  is  tubu- 
lar, in  others  club-shaped  ;  in  some  balloon-shaped  ;  in  some  even  .■spiral  the 
whorls  of  the  coils  either  united  or  free ;  but  in  all  cases,  so  far  as  we  know, 
the  plates  are  arranged  in  vertical  rows,  which  sometimes  diverge  at  intervals, 
and  apparently  in  all  of  them  the  edges  of  the  plates  —  not  their  substance 
—  are  perforated  by  pores  or  clefts. 

A  porous  sac  is  also  found  in  the  BelemnocrinidoB,  and  probably  exists  in 
the  Heterocrinidoe,  but  nothing  is  known  of  the  other  disk  plates  in  these 
families. 

In  the  Encrinidae,  according  to  Wagner,*  the  ventral  disk  rises  to  about 
the  height  of  the  second  costals,  where  it  contracts  abruptly  to  one  half  its 
diameter  at  the  base,  and  is  surmounted  by  a  small  cone.     The  peripheral 


•  Zeitschr.  d.  Deutsch.  Gesellscli.,  1887,  pp.  822  to  823. 


MORPIIOI.n(.^\L    .'ART. 


117 


pnrt  consists  of  Htnnll  limestone  partii, -s,  or  irregi  lar  plutos.  nn<l  was  ovi- 
dontly  (lexil)le ;  wliilc  the  conical  part,  wliieli  is  coinjwsod  ol  rpor  piowf* 
appears  to  be  almost  riyid.  Notliing  is  said  about  atiibiilnrra,  whicli  v^^^ 
probalily  not  visil)le  in  the  specimen.  That  the  cone  ro]  -^Mit"  a  ^1  rt 
ventral  sac,  and  that  the  allinities  of  the  P]ncrinidn)  are  with  llio  Fisiiitata. 
and  not  with  thi)  Apiocrinidtu  and  other  Neo/oic  Crinoids  as  hen'tufoco, 
supposed  by  Miller,  Miillcr,  Zittcl  nnd  Carpenter,  U  clearly  shown  from 
Wagner's  description. 

Among  A|>iocrini(ln)  do  Loriol  observed  the  togmen  in  Apiorr'nvii^  rnissij- 
mini*  a  species  with  larj^'c,  massive  plates  interposed  between  the  rays,  and 
in  which  tho  plates  of  the  cup  gradually  pass  into  the  tegmen,  which  consists 
of  rather  heavy  plates.  Tho  interbrachial  plates  were  regarded  by  Carpenter 
ns  "calyx"  interradials,  i  n.  homologous  with  the  interbrachials  of  the  Acti- 
nocrinida',  the  plates  of  tho  tegmen,  however,  as  "disk"  plates,  —  a  position 
which  was  controverted  I)y  us.t  We  asserted  that  if  those  plates  were 
"  calyx  "  interradials,  they  should  bo  followed  by  a  "  vault ; "  but  if  tho 
tegmen  was  a  disk,  then  the  plates  between  tho  rays  also  had  to  bo  con- 
sidered as  disk  plates.  We  came  to  this  conclusion  upon  ascertaining  that 
the  plates  of  the  tegmen  form  a  continuation  or  extension  of  those  in  the 
cup.  The  plates  of  the  two  hemispheres  in  most  cases  pass  imperceptibly 
from  one  into  the  other,  and  have  the  most  intimate  relations. 

Aplncrlmin.  is  not  the  only  Neocrinoid  genus  as  to  which  there  have  been 
doubts  respecting  the  homologies  of  tho  interbrachial  plates.  GKddinh'rriiuis 
is  morphologically  in  exactly  tho  same  condition,  and  the  recent  genus  Thwi- 
matucrimis  has  five  largo  plates  interposed  between  the  radials,  resting  upon 
the  basals,  and  followed  by  very  minute,  irregular  pieces,  which  j;r,adually 
pass  into  the  tegmen.  Also  in  many  of  the  IchthyocrinidoB  the  plates  be- 
tween the  rays  are  large  and  heavy;  while  those  of  the  tegmen  are  ill-formed 
nnd  unusually  small.  Ghjptocrimis  has  minute,  irregular  pieces  in  the  teg- 
men, and  well  defined  and  regularly  arranged  plates  in  the  cup.  In  all  these 
cases  Carpenter  took  tho  larger  plates  to  be  "  calj'x  interradials,"  but  called 
the  others  "  disk  plates,"  although  tho  former  occupy  relatively  tho  same 
position  as  the  smaller  ones,  and  as  the  disk  plates  of  the  Comatulnc,  CaJamo- 
crinns,  nnd  the  Pentacrinida?.  Our  recent  studies  show  plainly  that  neither 
tho  condition  of  these  plates,  nor  the  presence  or  absence  of  the  ambulacra 

•  Pnlcont.  Fratif .,  Ire  s^ric ;  Aiiim.  Invert.,  Criiioidcs,  p.  272. 
+  Revision,  Part  III.,  pp.  63,  72,  aud  137. 


^ 


lis 


THE  tUIXOIDKA   CAMKUAIA   OF   NORTH   AMKRICA. 


t   \ 


I  ; 


in  tliu  tegiiti'ti,  uimbloM  im  tu  di><i'riMiiniito  bt>tweon  purixuinic  mid  vault  pieccB; 
ami  tlii.'*  led  im  tu  iii(|iiirc>  wliutlivr  hucIi  a  dUtiiictiuii  uctiially  vs'n^ia  iit  any 
group. 

After  it  wax  demonstrated  that  the  ventral  Murfaco  of  Taxdcriiiiin  i«  a  tnio 
ili.sl<,  we  liecaine  couviiieed  tiiat  our  views  reMpeeting  vault  and  disk  would 
have  to  l)u  iiioililied  as  to  other  groups  also,  or  be  altogether  almudoued.  The 
latter  was  done  in  1892,  in  a  paper  on  "  The  I'erisomic  Plates,"  *  in  whieh 
wo  endeavored  to  show  that  the  so-called  "vault"  of  the  older  Crinoids 
is  a  inodilied  disk.  This  interpretation  has  since  been  necepted  by  Agassiz, 
Carpenter,  and  Huther,  who  agree  that  the  use  of  the  term  "vault"  should 
1)0  abandoned  in  a  morphological  sense.  The  modifications  that  took  place 
arc  most  apparent  among  the  Camerntn,  in  which  there  in  a  marked  increasu 
in  the  si/e  and  rigidity  of  the  plates,  which  reached  itM  culmination  among 
Carbonil'erous  forms. 

The  t<'j;iuen  of  Paheozoic  Crinoiils  is  often  formed  into  ridges,  which 
diverge  from  near  the  centre  to  the  arm  bases.  These  ridges,  which  aiu 
liest  defined,  and  occur  most  freriuontly,  among  Silurian  Cnmerata,  are  formed 
cither  by  covering  pieces  or  the  interambulacral  plates.  Such  ridges  also 
occur  uiion  the  di.sk  of  the  Couiatuloj,  but  they  are  formed  exclusively  by 
the  amliuliicral  plates.  Among  the  earlier  forms  ridges  of  this  kind  have 
been  observed  in  Actituirrliuis  (j)ilnijH(iii(juliiiis,1[  Ifidinicriinis  anHtftis.^  Mursii- 
jiiocn'iiiis  (lijinssns,^  Jftrf<iij)ii)rrliiiis  rdilldtiis  (Plate  VIII.  Fig.  15);  and 
Pldtijcriiiiifi  symmctrlcHs  (Plate  LXIX.  Fig.  Ifi) ;  in  all  of  which  the  mouth 
is  closed  either  by  the  orals,  or  in  their  absence  by  the  uppermost  covering 
pieces,  which  interlock  with  those  of  adjoining  ray.s.  Very  prominent  ridges 
occur  also  upon  the  disk  of  TaxorriiniH  liitirinaliiis  (Plate  III.  Fig.  11),  in 
which,  fontrary  to  the  preceding  forms,  mouth  and  food  grooves  arc  opened 
out.  The  ventral  structure  of  this  species  bears  a  remarkable  resemblance 
to  that  of  the  young  Pluti/criiiHH  mjmmetrkus  (Plate  LXIX.  Fig.  Ic);  nil 
that  is  recjuirod  to  convert  the  "vault"  of  this  Phiti/criniis  into  a  disk  like 
Taxocriiiiin,  is  that  its  orals  should  be  parted  enough  to  let  the  ambulacra 
pass  in  to  the  centre  between  or  over  their  edges.  Its  resemblance  is  equally 
striking  to  the  recent  Culamocrimdi  and  Ilijocrbuis ;  n  slight  receding  of  the 
posterior  oral  and  movable  covering  pieces  would  bring  the  three  forms  sub- 
stantially into  the  same  condition,  all  of  which  shows  that  the  closure  of  the 


•  Procml,  Acnd.  Nnt.  Scl.  Pliila.,  pp.  315-375. 
+  Icoiiditr.  Clin.  Siipc,  Plate  XVI.  Fig.  28. 
§  Ibid.,  Plate  X.  Fig.  10. 


t  Ibid.,  Plate  XXVII.  Fig.  5. 


^|k 


M(HU'II()I,0(iK'AI-   I'AHT. 


110 


mouth  in  tlic  oMit  Ciiiioids  is  not  acconiplislu'il  hy  miy  mlditioiiMl  ,«i't  of 
pliiti'H,  but  hy  tilt'  pliitcM  wliifli  in  rocont  CiinoiilM  .xini'oiinil  tin*  mouth. 

CiiHCH  in  whicit  the  amhiiiiicni  enter  tlie  tegmun  from  licinnili  what 
>voro  funiiei'ly  ciilled  the  internulial  donu'  plitteM,  are  I'oinid  in  almo.«t 
every  family  of  the  (.'ami'rata.  They  oceiir  more  fri'ijin'Mlly  aiiioni:  jjeiieru 
in  wiiicli  the  ventral  Hurfaeo  is  paved  liy  Hmall  irregular  pieces.  ^u(h  as 
(I'l^jifiifriiiiis,  lidiiirruiiifi  and  Airhu'drriniis ;  hut  alno  in  otht-rs.  A  mo.xt 
instruetivo  ca-ie  of  this  kind  is  preMented  hy  n  rather  younj,'  ^-pecimen  of 
Mtyintorrlinig  miliil'm  (Plate  XLVII.  B'ign.  ^n,  l>),  in  wliieh  not  oidy  covering 
jjiccex,  hut  well  dermed  side  pioeos  enter  the  calyx.  The  ventral  pavement 
connists  of  moderately  large,  irregularly  arranged  plates,  whieh  ;:radnally 
decrease  in  .size  toward  the  arms.  The  tegmen  is  perfectly  Hat,  except  near 
it8  outer  margin,  where  it  is  distinctly  plicated  to  form  the  large  openings 
for  the  ponderous  arms.  At  tin-  iinier  Hat  portions  the  aml)ulacra  are  con- 
cealed, hut  at  the  plicated  outer  part  hotii  covering-  and  side-pieces  come  to 
the  surface,  and  are  visible  for  some  distance.  It  is  now  quite  instructive 
that  in  another  more  adult  specimen  of  the  .same  species  (Plate  Xl<\'ll.  Fig. 
G)  the  parts  of  the  amhulacra  which  in  the  former  Hi)cciinon  were  exposed, 
are  roofed  over  from  both  8ido8  hy  interambulacral  plates  of  snhseiiuent 
growth.  This  observation  throws  important  light  upon  the  development  of 
the  so-called  vault  of  the  Camerata  generally.  It  shows  that  the  same  system 
of  plates,  which  in  a  young  specimen  is  in  p^irt  /«^tv-ambidacral  only,  may 
gradually  become  .'(/^^nz-ambulacral  in  apothei . 

Wo  find  a  somewhat  dilTerent  structure  m  a  finely  preserved  adult  speci- 
men o(  JfnjistocrtHKii  Kransi  (Plate  XLVII.  B'ig.  ]f>),  in  which  in  tliroc  of  its 
rays  two  series  of  large,  nodose,  alternating  plates  pass  out  from  near  the 
orals  in  the  direction  of  the  ambulacra.  The  series  are  freqiicntly  inter, 
rupted  by  .small,  Hat  pieces,  which  are  interspersed  among  the  larger 
ones.  In  some  places  the  arrangement  of  the  larger  plates,  which  are 
evidently  covering  pieces,  is  ns  regular  as  in  any  Phttijcrhms  ;  but  at 
others,  owing  to  the  interference  of  the  smaller  plates,  quite  irregular, 
especially  in  the  two  rays  to  the  right  of  the  anus,  where  scarcely  any 
two  of  those  plates  are  continnou.s.  It  is  most  remarkable  that  in  no 
two  specimens  of  this  species  is  the  arrangement  of  the  covering  pieces 
alike.  In  .some  of  them,  only  the  five  large  bifurcating  plates,  the  ,«o-callcd 
radial-domo  pieces,  arc  in  view,  followed  by  ten  others  of  a  second  order. 
The  ventral  structure  of  this  species  not  only  ofTers  a  good  proof  that  the 


'!  ' 


£'l  ! 


120 


THE  CUINOIDKA  CAMKRATA   OF   NORTH  AMKRICA. 


so-calletl  nuliiil  dome  plates,  aw  before  suggested,  are  extravaganlly  developed 
covering  pieces,  but  indicates  that  the  "vault"  was  I'ornied  by  a  gradual 


of  the  hiteninibultj 


alony  the  li 


jI"  the  anibulii 


ithei' 


rxtensum  oi  the  inteninibulacral  areas  along  the  Inie  ol  the  aniijulacra,  either 
covering  them  entirely,  or  encroaching  upon  them  and  leaving  the  more 
prominent  plates  exposed. 

In  GI)/ptocrhu(s  and  Jictcocrhius  the  toginen  is  essentially  in  the  same 
condition  as  in  JIc(jlstucrint(s  nuhilin,  but  no  orals  are  distinguishable,  and 
the  whole  ventral  surface,  including  tiie  median  portions,  is  covered  by 
minute  granular  pieces.  The  middle  part  is  evenly  convex,  but  toward 
the  perii)liery  there  are  ridges  leading  to  the  arm  bases,  and  on  top  of 
these  ridges  the  covering  pieces  are  exposed.  In  the  median  portions  the 
.".mbulacra  were  evidently  subtegminal.  being  rooled  over  by  superimposed 
inter-ainbulacral  plates,  which  form  a  continuous  intcgmnent  over  them. 

A  careful  study  of  the  difleront  tcgmens  which  are  foiiud  among  the 
various  families  of  the  Camerata  shows  that  the  ambulacra,  as  a  rule,  are 
subtegminal  in  species  with  a  high  dome  or  bulging  at  the  arm  bases,  but  in 
species  with  a  llat  or  depressed  surface  they  are  generally  tcgmini'.l,  or 
become  tegminal  before  entering  the  arms.  They  are  expo.sed  in  forms  like 
"Actiiitivriiiiis"  qiiinqu(iii(jiihiri)i,  Ildbrocriniis  uriHtttd^,  Mitrmijiiocrhnis  dcjjiXfisiis, 
and  (UiijitihTinuti  unnitKS,  —  species  with  a  low  disk  ;  but  they  are  necessarily 
subtegminal  in  genera  such  as  Cavturrinitti,  Slj)JtoHucrliii(!i,  etc.,  in  which  the 
tegiiieu  is  high  and  conical.  The  condition  of  the  ambulacra,  therefore, 
whether  tegminal  or  subtegminal,  does  not  represent  an  es.sential  structural 
feature,  but  is  a  natural  consequence  of  dilferences  in  the  form  and  construc- 
tion of  the  teginen  in  the  respective  species. 

jSow  if  it  is  true  that  a  plated  integument  was  formed  in  GI>/j)tocri)ius 
and  Jlt(jisiiicruuis  by  the  profuse  development  of  the  interambulacral  plates, 
and  their  gradual  fusion  along  the  line  of  the  ambulacra  over  a  part  of  the 
disk,  it  would  seem  to  follow  that  the  more  substantial  vaults  o(  Actinocrinus, 
Butocriinis,  and  Plti/scfovriiius  may  have  originated  in  ii  similar  way,  and  that 
the  body  of  these  forms  also  was  covered  by  a  single  set  of  plates.  This 
seems  to  be  confir'ned  by  a  very  instructive  specimen  of  Phi/sducriinis,  in 
which  the  delicate  structure  at  the  inner  door  is  shown  in  excellent  preser- 
vation (Plate  V.  Fig.  14).  The  specimen  has  the  great  advantage  of  being 
free  from  any  silicious  coating,  such  as  obscured  the  structure  in  previ- 
ous specimens  of  this  kind.  The  outer  surface  of  the  tegmen  is  composed 
of  moderately  large,  smooth  pieces,  of  irregular  form,  closely  fitted  together 


, 


MORPHOLOGICAL   PART. 


121 


at  nil  sides.  There  are  no  orals,  but  near  its  outer  margin  tliore  are  radial 
dome  plates  of  a  first  and  second  order,  which  are  readily  rccogni/.ed  by 
their  largo  size  and  greater  convexity.  Other  ainbulaeral  plates  are  not 
visible.  Examining  the  inner  floor,  we  find  the  same  arrangement  of  plates, 
and  actually  the  same  plates  as  at  the  outer  side,  but  the  general  aspect  is 
tot4dly  different.  They  look  like  sharply  delineated  stars,  with  as  many  rays 
as  there  are  sides  to  the  plates.  There  are  abrupt  depressions  between  the 
star-rays,  which  on  meeting  corresponding  depressions  of  adjoining  plates, 
form  deep,  sometimes  cavernous  pits,  more  or  less  undermining  the  plates, 
and  which  seem  to  have  communicated  with  one  anotlier  by  imbedded  pas- 
sages all  along  the  teguien.  The  star-shaped  plates  extend  over  both  the  peri- 
stome and  ambulacra,  being  occasionally  interrupted  by  small,  supplementary 
pieces,  apparently  solid.  Thus  the  tegmen  o(  Plii/fctocriiiiix  is  not  composed 
of  two  distinct  sets  of  superimposed  plates,  as  heretofore  supposed,  but  of  one 
set  only,  of  which  the  plates  arc  solid  externally,  and  perforated  or  honey- 
combed throughout  their  inner  portions.  The  presence  of  but  one  set  is 
further  confirmed  by  the  position  of  tiie  ambulacra,  which  follow  the  inner 
floor.  This  is  of  importance,  for  if  the  upper  or  solid  part,  as  was  supposed 
to  be  the  case  in  the  allied  BiiforriiiKs  and  Artiiiocriinis,  represented  a  vault, 
and  the  inner  part  a  disk,  the  ambulacra  should  lie  between  them  ;  whereas 
in  this  case,  lying  below  them  both,  they  would  be  covered  by  two  integu- 
ments, first  by  the  overlapping  interainbulacral  plate.s,  and  then  by  a  vault, 
—  an  arrangement  in  the  highest  degree  iinprol)able.  The  ambulacral  skele- 
ton itself  is  not  preserved  in  the  specimen,  but  the  place  it  occupied  is  clearly 
indicated  by  .shallow  grooves,  formed  by  a  thickening  of  the  plates  all  along 
the  interradial  spaces. 

The  internal  structure  of  Fliyiictocrii)t(s  gives  us  the  key  to  that  of  Bato- 
criiius,  Donjcrlnm,  Actinocrinns,  Teklorriniis,  and  of  the  Camerata  generally, 
in  all  of  which,  as  wo  no  longer  doubt,  there  is  but  a  single  integument ; 
and  the  part  which  wo  have  heretofore  regarded  as  a  disk  forms  a  portion 
of  the  same  set  of  plates,  which  are  perforated  at  the  inner  floor  so  as  to 
produce  the  numerous  caverns  and  passages  above  described.  Those  pas- 
sages and  pits  may  have  served  for  the  free  circulation  of  water,  and  we 
think  it  highly  jirobable  that  the  older  Crinoids  had  a  very  complex  .'ascular 
water  system,  extending  all  tlie  way  from  the  interradial  plates  of  the  dor.'^al 
cup  to  the  top  of  the  ventral  disk.  This  complex  system  was  probably 
not  required  in  recent  Crinoids,  in  which  many  of  the  plates  are  perforated 


I 


I 

i 

i  , 
f  ^ 


) 


^ 


16 


f    ' 


122 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


[■^  \    t 


it 

11  i 

\ 


ti 


i! 


througliout,  by  means  of  which  the  surrounding  water  is  brought  in  direct 
contact  with  any  part  of  the  body. 

There  are  good  reasons  for  believing  that  in  the  Camerata  the  water  for 
respiration  was  introduced  near  the  arm  bases  through  small  openings,  de- 
scribed by  us  as  respiratory  pores,  and  then  followed  the  canals  and  passages 
along  the  test.  Such  openings  have  been  observed  not  only  among  the  Actino- 
crinida3  and  Batocrinida),  but  also  among  the  Melocrinida)  and  Rhodocrinida\ 
In  tiie  genus  Dohttocrlnus,  they  are  large  and  slit-like  as  in  Ophiurids,  in  Batu- 
crinits  and  Actinocrinus  round,  and  in  Gilbertsocrinits  at  the  outer  end  of  long 
tubes.  The  openings  are  always  located  between  the  rays  and  their  main 
divisions,  a  little  above  the  arm  regions.  Some  species  of  Dolatocrinun  have 
from  four  to  six  to  <^^^c^\  interradius,  and  two  to  four  to  each  interdistichal 
space,  all  arranged  horizontally.  In  Dolatocrinus  this  vascular  system  prob- 
ably extended  only  over  the  peripheral  portions  of  the  disk,  for  the  inner 
floor  at  the  middle  portion  is  perfectly  smooth  in  the  specimens.  In  Bato- 
crimis  and  Tcleiocriniis  it  probably  extended  to  the  outer  margins  of  the  orals 
(Plate  V.  Figs.  16  and  17)  ;  while  in  Physctocrinus,  when  the  orals  are  un- 
represented, it  apparently  occupied  the  whole  tegmen. 

We  now  come  to  the  ventral  structure  of  Sijjhonocrinus.  It  will  be 
remembered  that  in  S.  armosus  not  only  tlie  .ambulacra,  but  large  portions 
of  the  anal  tube,  are  subtegminal,  and  that  the  latter  lies  across  the  mouth 
and  covers  portions  of  the  ambulacra.  The  tube,  however,  in  two  other 
species  of  this  genus  opens  out  centrally,  thus  showing  that  the  subtegminal 
condition  of  the  tube  had  no  important  bearing  upon  the  general  structure 
of  the  disk.  As  we  understand  the  case,  the  anal  tube,  which  is  actually 
the  outer  end  of  the  hind  gut,  in  place  of  becoming  free  ind  piercing  the 
central  part  of  the  disk  as  in  the  other  two  species,  was  roofed  over  in 
S.  armosKS  by  the  interambulacral  pieces  in  a  somewhat  similar  manner  to 
the  calyx  ambulacra  of  Merjistocrinus. 

Now  if  it  is  true  that  in  forms  like  Physetocrinns,  Batocrinm,  Actinocrinus, 
and  Siphonocrinus,  there  is  no  second  integument,  .'t  may  be  considered  as 
proved  that  a  "  vault,"  as  an  independent  structure,  did  not  exist  in  any  of 
the  Camerata,  nor,  in  fact,  in  any  of  the  other  groups,  and  that  the  structure 
to  which  the  term  has  been  applied  in  these  forms  was  evolved  phylogenet- 
ically  from  the  disk  of  the  primitive  types,  of  probably  Pre-Silurian  time. 

The  disk  of  the  Fistulata  also  experienced  notable  changes  in  its  paloeon- 
tological  development,  but  these  took  place  on  different  lines.    The  plates 


*!S 


:|l 


\\ 


MORPHOLOGICAL  PART. 


123 


of  the  tegnien  at  no  time  attained  the  rigidity  and  large  size  of  that  in 
the  Camcrata,  nor  did  those  of  the  doraal  cup,  with  the  exception  of 
the  anal  plates,  undergo  any  material  alterations.  It  was  the  ventral  sac 
which  gave  to  this  group  its  characteristic  feature.  The  sac  in  the  earliest 
forms  was  quite  small,  but  it  soon  attained  such  enormous  dimen.sions  that 
already  in  the  Silurian  it  constituted  the  greater  part  of  the  cal^x.  At  the 
close  of  the  Carboniferous,  however,  it  dwindled  down  almost  as  rapidlj-  to 
its  former  insignificance,  so  that  it  is  represented  in  Cromifocrimis,  L'lijKwhy- 
crimis,  Erisocrimts,  and  Encrimis  by  a  very  short  cone.  The  resjjiration  of 
the  Fistulata  was  apparently  directly  through  the  test,  but  only  at  the 
posterior  side  of  the  calyx.  It  took  place  either  by  means  of  pores  along  the 
sac,  or  by  a  madreporite  placed  in  front  of  the  sac.  The  respiratory  pores 
of  the  Fistulata  only  pierce  the  edges  of  the  plates ;  while  the  water  pores  of 
recent  Crinoids  pass  through  the  whole  plate.  The  mode  of  respiration  of 
the  Larviformia  is  unknown.  They  had  apparently  no  openings  in  the 
calyx  except  the  anus,  but  they  possessed  pores  along  the  arms  at  the  sides  of 
the  covering  pieces,  which  may  have  served  respiratory  purposes. 

Most  of  the  IchthyocrinidsB  have  interbrachial  plates,  which  in  some 
species  are  large  and  massive,  in  others  small ;  and  some  are  regularly 
arranged,  others  irregularly.  The  mouth  is  opened  out,  the  ambulacra  are 
tegminal,  and  rest  in  an  integument  of  very  small,  ill-formed  pieces,*  which 
extend  to  t!ie  ir>,erradial  plates  in  the  cup,  and  those  at  the  sides  of  the 
brachial  appendages.  The  small  plates  form  pouches  or  sacs,  which  some- 
times reach  to  the  second  or  third  bifurcation.  The  median  lines  of  these 
pouches  are  occupied  by  the  ambulacra,  which  converge  to  the  mouth,  sepa- 
rating the  orals. 

Here  we  have  among  Palaeozoic  Crinoids  a  tegmcn,  which  has  all  the 
characteristics  of  the  disk  of  living  species,  down  to  an  uncovered  mouth  and 
open  food  grooves,  thus  demonstrating  conclusively  that  the  disk  as  a  ventral 
structure  is  not  confined  to  the  Neocrinoidea.  The  discovery  cf  this  fact  led 
to  entirely  new  ideas  touching  the  derivation  of  these  groups.  Before,  it 
had  been  supposed  that  the  "  vault "  ceased  to  exist  in  Neozoic  times,  or  was 
reduced  to  the  orals.  It  may  now,  we  feel  assured,  be  considered  as  estab- 
lished that  the  structure  of  the  tegmen  in  the  oldest  Palfeozoic  Crinoids, 

•  We  carefully  removod  the  nrins  in  scvprnl  well  pirsrrved  specinieiis  of  Oiiycliopriiiiis  Ulriehi  mid 
0.  (liversiif,  niid  in  several  instances  fonnd  portions  of  the  ventral  disk  imbedded  in  the  dorsal  eup,  lying  upon 
the  inner  Hoor  of  the  plates.  The  disk  of  these  ajiecies  must  have  been  extremely  pliable,  and  probably  con- 
sisted iu  part  of  soft  tissues. 


^1 


124 


THE  CRIXOIDEA   CAMERATA  OF   NORTH   AMERICA. 


1    U 


I  : 


although  the  mouth  in  most  of  tliem  remained  closed  throughout  life,  was 
not  morphologically  distinct  from  that  of  the  Crinoids  of  existing  forms,  and 
that  the  so-called  "  vault  "  has  been  developed  gradually  from  the  disk. 
The  Camerata,  therefore,  cannot  be  the  progenitors  of  recent  Crinoids  ;  they 
represent  a  side  group,  which  in  the  course  of  Palasozoic  time  departed 
essentially  from  the  primitive  type,  reaching  the  culmination  of  extravagance 
in  form  and  size  in  the  Carboniferous,  and  becoming  extinct  at  the  close 
of  tiiat  epoch. 

B.     T/ic  Ami  Plates  and  the  Anus. 

The  Anal  plates  bear  a  most  important  part  in  the  phylogeny  of  Palaeo- 
zoic Crinoids,  and  are  also  of  high  importance  in  respect  to  classification. 
Some  writers  apply  the  term  "  anal  plates"  indiscriminately  to  all  interradial 
plates  of  the  posterior  area,  while  others  restrict  it  to  the  plates  directly  or 
indirectly  connected  with  the  anus.  We  apply  the  term  to  the  latter  plates, 
but  only  to  such  of  them  as  take  part  in  the  dorsal  cup ;  the  others  being 
plates  of  the  anal  tube  or  ventral  sac. 

The  anal  plates  in  all  Camerata,  when  present,  occupy  the  median  line  of 
the  posterior  area,  so  as  to  divide  the  interbrachial  plates  into  two  equal 
sets ;  and  in  rows  containing  an  odd  number  they  have  the  effect,  as  it  were, 
of  breaking  up  the  middle  plate  into  two,  even  in  cases  where  no  anal  plate 
is  inserted  between  the  segments.  The  latter  is  the  case  in  the  Actino- 
crinida?,  in  which  the  first  interbrachial  row  at  the  posterior  side  always 
consists  of  two  plates,  in  place  of  one  as  in  each  of  the  others ;  though  all 
have  an  anal  plate  between  the  radials,  and  an  extra  plate  in  the  second 
interbrachial  row.  In  the  Batocrinida?  and  Tln'sanocrinidas  there  are  two 
interbrachial  pieces  above  the  first  anal,  which  enclose  a  second  anal  piece. 
The  Hexacrinidae  have  but  one  large  anal  plate  resting  upon  the  basals. 
The  Eucalyptocrinida)  have  no  anal  plate  at  all,  the  five  interbrachial  areas 
being  perfectly  symmetrical.  Such  is  the  case  also  in  Dolatocrimis,  Stereo- 
crinus,  Centrocrbius,  AUocrimis,  and  PatelUocrinus ;  while  the  typical  Melo- 
crinidae  have  an  anal  plate  in  one  or  more  of  the  upper  rows.  Similar 
variations  occur  a-^^ong  the  Rhodocrinidae,  in  which  anal  plates  may  be 
either  present  or  absent.  The  Platycrinidae  have  no  special  anal  piece,  but 
the  middle  plate  of  the  proximal  row  at  the  posterior  aide  is  considerably 
enlarged,  and  evidently  united  the  functions  of  an  anal  plate  with  those  of 
the  regular  interradial. 


I 


■>  * 


MORI'HOLOGICAL  PART. 


125 


H 


It  tliiia  appears  that  the  anal  plates  vary  consitlerably  in  their  position 
and  distribution,  and  in  some  groups  are  absent  altogether.  As  a  general 
rule,  they  are  largely  represented  in  species  with  a  strong  tube,  or  a  protrud- 
ing lateral  opening;  while  in  forms  in  which  the  anus  is  central,  as  in  the 
Eucalyptocrinidic,  or  comparatively  small,  they  are  either  wanting  or  but 
feebly  represented.  The  anus,  although  more  or  less  influencing  the  whole 
posterior  area,  did  not  necessarily  require  the  introduction  of  anal  plates, 
and  when  the  tube  was  small,  an  enlargement  of  the  regular  interbrachinl 
plate  sufficiently  increased  the  width  of  the  area.  The  anal  plates,  therefore, 
do  not  appear  to  constitute  an  essential  element  of  the  Crinoids,  but  seem 
to  be  supplementary  pieces,  introduced  when  the  space  was  insufficient  to 
accommodate  the  tube. 

Among  the  Fistulata,  the  term  "anal  plates"  has  been  npplicd  to  two 
plates  of  different  origin,  the  one  radial,  and  the  other  interradial.  Tiie 
latter  is  the  hoinologue  of  the  "  special "  or  "  first"  anal  plate  of  the  Came- 
rata,  and  rests  upon  the  truncated  posterior  basal.  When  there  are  two 
plates  in  the  species,  as  in  most  of  the  Poteriocrinida?,  and  occasionally  in 
other  families,  the  second  —  which  is  actually  the  first  or  lowest  in  point 
of  position  —  is  located  obliquely  to  the  right  of  the  first,  so  as  to  encroach 
more  or  less  upon  the  proximal  face  of  the  right  posterior  radial.  Its  lower 
angle  rests  upon  the  upper  sloping  faces  of  the  adjoining  basal,  its  upper 
face  supporting  the  first  plate  of  the  tube,  which  in  some  of  these  genera  is 
partly  enclosed  in  the  calyx.  To  understand  the  position  of  the  lower  plate. 
it  should  be  noted  that  throughout  the  modifications  which  took  place  in 
tlie  posterior  interradius  in  geological  time,  this  plate  always  retained  its 
alternate  arrangement  with  the  basals,  and  occupied  a  radial  position  from 
the  beginning.  Its  form  was  changed,  and  to  some  extent  its  relation  to 
surrounding  plates,  by  the  increasing  width  of  the  ventral  sac,  which  caused 
a  displacement  of  the  nrm-bcaring  plates.  The  oblique  position  which  the 
plate  holds  toward  the  posterior  basal  and  the  regular  anal  plate,  and  the 
latter  toward  the  first  plate  of  the  tube,  gives  to  these  pieces  a  sort  of 
alternate  arrangement,  which  is  continued  throughout  the  tube. 

The  changes  that  took  place  among  the  anal  plates  in  the  various  groups 
of  the  Fistulata  have  been  discussed  by  us  at  different  times,*  from  which  it 
appears  our  views  have  undergone  considerable  modification  as  the  result  of 

•  1879,  Revisinn,  Part  I.,  pp.  71  nnd  72;  18S.S,  Amer.  Joiirn.  Sci.,  Vol.  XXVI.,  pp.  365  to  377;  1885, 
Rev.  Pt.  Ill,,  Sect.  I.,  pp.  11, 12,  40;  and  1886,  ibid..  Sect.  II.,  pp.  196  and  210. 


n 


I 


126 


THE  CRIXOIDEA  CAMERATA  OF  NORTH  AMERICA. 


H 


further  research.  The  .subject  wa.s  also  discussed  by  Dr.  P.  H.  Carpenter  In 
his  paper  "  On  the  Kehvtions  of  Ilijhocrimis,  Baerocrinua  and  Hi/boci/tititcs,* 
and  lately  by  Mr.  F.  A.  Bather  in  a  paper  "  On  the  Briti.«h  Fossil  Crinoids."t 
Bather  agrees  with  us  and  with  Carpenter  that  the  radially  disposed  plate 
is  a  posterior  inferradial,  which  in  some  groups  took  on  anal  functions. 
He  gave  it  the  name  "  radianal,"  which  we  have  accej)ted,  but  we 
apply  the  term  only  when  the  plate  actually  serves  as  a  support  of  the 
tube.  Ro.<»pecting  the  origin  of  the  other  plate,  which  we  take  to  be  a 
special  interradial,  he  advances  views  from  which  we  regret  to  be  obliged 
to  di.ssent.  His  idea  is  that  this  plate  "  originated  as  a  plate  morphologically 
corresponding  to  an  ordinary  brachial,"  and  lie  undertakes  to  prove  that  in 
its  paliuontological  development  it  pa.ssed  down  from  above  the  radials  to  the 
basals,  and  between  the  radials.  He  calls  it  a  "  brachianal,"  —  a  term  which 
becomes  meaningless  if  it  proves  to  be  interradially  disposed.  To  this  plate 
we  apply  the  general  term  "  anal  plate,"  as  we  take  it  to  be  the  homologue 
of  the  anal  plate  of  the  Antcdon  larva,  and  structurally  identical  with  the 
first  anal  plate  of  Actinocrbius. 

We  give,  on  Table  C,  a  series  of  diagrams  to  illustrate  the  development 
of  the  anal  plates,  in  which  the  "brachianal" — of  Bather  —  is  marked  x. 
The  radials  are  designated  by  the  letter  R,  and  when  compound,  the  lower 
section  —  the  inferradial,  which  is  also  the  "radianal"  when  it  helps  to 
support  the  tube  —  by  R.      The  tube  plates  are  called  t. 

To  the  Plate  R  we  have  already  alluded  in  the  chapter  on  the  radials, 
discussing  those  forms  in  which  it  represents  a  part  of  the  radial,  and  lies 
in  a  vertical  line  with  R.  Let  us  now  consi<ler  tliose  forms  in  which  it  serves 
as  anal  plate.  Among  these  forms,  of  which  rokriocriiuts  may  be  regarded 
as  the  type,  four  of  the  five  radials  are  simple,  and  the  Plate  .r,  which  is  gen- 
erally represented,  rests  upon  the  basals.  The  ventral  sac,  which  in  the  ear- 
lier forms  was  rather  insignificant,  had  rapidly  increased  in  si/e  at  the  close 
of  the  lower  Silurian,  in  such  a  manner  that  the  sloping  upper  faces  of  the 
radials  were  insufficient  to  support  it,  and  certain  cltanges  in  the  structure  of 
the  dorsal  cup  became  inevitable.  It  thus  happened  that  the  two  posterior 
radials,  which  had  previously  been  in  contact  laterally  (locriiiKs,  Fig.  9)  were 
now  parted,  and  the  Plate  .r  was  introduced  to  fill  the  vacant  space  (Dcn- 
(Irocrinus,  Fig.  13).    The.se  modifications,  however,  did  not  afTect  the  position 


I   \ 


*  Quart.  Journ.  Geol.  Soo.  London,  Vol.  XXXVIII.,  pp.  298-312. 

t  Ann.  ami  Mag.  Nat.  Hist.  (Gth  Scr.),  Vol.  V.,  April,  1890,  pp.  319  to  331. 


\   ! 

\  \ 

i  ' 

^  ^ 

1 

M 


f'\ii 


MORPHOLOGICAL  PART. 


V2 


of  the  inferradiiil,  which  retained  Its  place  between  the  npper  sloping  faces 
of  two  basals,  only  changing  its  outlines  to  conform  to  the  shape  of,  and  fit 
in  between,  adjoining  plates.  In  the  Carboniferous,  in  which  the  ventral  sac 
attained  its  greatest  dimensions,  and  the  lower  faces  of  the  costals  frequently 
fill  up  the  whole  width  of  the  radials,  leaving  no  space  upon  their  distal  faces 
for  an  attachment  of  the  tube,  the  superradial,  Ji,  was  shifted  to  the  right, 
into  a  position  almost  directly  above  the  right  postero-lateral  basal,  and 
obliquely  against  the  inferradial  Ji'  {Poteriocrinm,  Fig.  2).  Finally  toward 
the  close  of  the  Carboniferous,  when  the  tube  was  reduced  to  its  primitive 
insignificance,  the  anal  plates  gradually  disappeared,  and  the  five  radials  re- 
sumed their  normal  position  as  in  Erisocrimts,  Stcmmatocrimts,  and  Encrinuii. 
This  is  entirely  different  from  the  interpretation  of  Mr.  Bather,  who 
reaches  the  conclusion  that  the  anal  plate  x  was  primitively  derived  from  a 
brachial,  and  that  in  geological  time  it  passed  down  from  above  into  the 
dorsal  cup.  He  regards  (oj).  cit,  p.  329)  "  tho.se  forms  as  primitive  in  wliicli 
the  radianal  is  more  of  a  radial  and  less  of  an  anal,  in  which  it  is  not  in  an 
asymmetrical  position  but  corresponds  to  the  other  lower  brachial  plates. 
Such  forms  are  locrinns,  Ileterocrimts ,  Eetenocrinus,  Anomalocrbms,  and  J\[a'n- 
crinus.  Now  in  all  these  forms  x-  is  supported  by  2i,  and  does  not  touch  I\". 
Obviously  then  x  is  not  derived  from  JI',  but  originates  above  Ji,  and  on  its 
left  side.  By  parity  of  reasonmg  we  assume  the  next  stage  to  be  repre- 
sented in  such  forms  ns  JFi/bocrimis  (I),  Ottaivacr inns,  Dendrocr inns,  and  Ilomo- 
crinus,  since  in  them  R  is  rather  more  asymmetrical.  In  these  .r  has 
passed  down  from  .ibove  R,  and  now  rests  with  its  lower  half  between  the 
right  and  left  posterior  radials,  being  supported  partly  by  Ji'  and  partly  by 
the  basal.  Carahocrinus,  Boiri/ocrinus,  and  similar  forms  are,  as  all  acknowl- 
edge, the  next  stages  in  the  shifting  of  the  radianal ;  in  these  z  has  sunk 
still  lower  into  the  dorsal  cup,  and  is  now  entirely  in  a  line  with  the  radials. 
...  In  Purisocrinus  and  Euspirocrinus  among  pinnuless  forms,  and  in  the 
Poteriocrinites,  another  change  has  taken  place  ;  the  radianal  has  passed 
through  a  revolution  of  90°,  and  the  lowest  plate  of  the  ventral  sac  {t)  has 
sunk  down  between  R  and  .r." 

Before  inquiring  into  the  validity  of  this  argument,  it  will  be  well  to  ascer- 
tain whether  the  plates  of  the  different  genera  which  Bather  calls  x  are 
structurally  the  same  thing,  for  an  error  in  this  respect  would  be  fatal  to  the 
whole  theory.  The  question  is,  is  his  plate  x  in  locrimis  and  J\fcrorrii)iis, 
which  rests  upon  the  one  marked  by  him  B  or  C,  and  that  resting  upon  R 


n 


s  J ;« 


128 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


■P^    I  i' 


ii' 


if  it 
I  ■ 


lU 


in  Ilijhocrinus,  and  R  in  Anomalocrinus,  homologouH  with  the  plato  of  Den- 
drocriniis,  Hmnocrinuti,  etc.,  wiiicli  is  supported  by  K  and  partly  by  the 
biisals,  and  also  with  the  plate  of  Poteriocriitiis,  which  re.sts  upon  the  basals 
and  against  the  radianal  Ii'  ?  This  question  was  not  discussed  by  Bather, 
though  we  had  expressed  views  different  IVoin  his  respecting  the  plate  x  in 
lutrinits  and  Jliwcrinua.  That  plate  was  regarded  by  us,  in  both  genera  (in 
locrimis  as  early  as  1879),*  as  a  plate  of  the  tube,  and,  so  far  as  we  know, 
we  never  made  any  statement  from  which  he  might  infer  that  we  thought  it 
represented  the  plate  x ;  yet  he  quotes  us  ii>  his  diagram?  as  if  we  had  done 
HO  in  1879. 

Instead  of  commencing  with  the  earliest  forms,  as  Bather  did,  we  begin 
with  the  simplest,  and  select  as  a  starting  point  the  genus  Ci/athocrinus,  which 
is  so  well  known  to  every  paUvontologist.  Ci/cit/iocrinxs  has  simple  radials, 
and  but  one  anal  plate,  which,  as  all  writers  agree,  represents  the  plate  x.  It 
rests  upon  tlie  truncated  upper  face  of  the  posterior  basal,  between  two  ra- 
dials, and  is  generally  followed  by  three  plates  of  the  tube  (Fig.  3),  of  which, 
as  in  the  Butocrinida),  the  two  at  the  sides  rest  to  an  equal  extent  against 
—  or  rather  upon  —  the  sloping  upper  faces  of  adjoining  radials.  The 
structure  of  G'raphiocriniis  de  Kon.  and  Le  Hon,  as  amended  by  us  in  1879,  is 
similar  to  that  of  Ci/afhorrinits.  This  genus  also  has  only  the  plate  a;  repre- 
sented, but  here  it  is  angular  at  the  upper  end  instead  of  truncated,  and 
supports  but  two  e(|ual  plates  of  the  tube.  This  produces  a  sort  of  bilateral 
.symmetry  in  the  posterior  side  of  the  tube,  each  plate  supporting  a  vertical 
row  of  hexagonal  or  subquadrangular  pieces. 

Next  in  order  we  take  DcndrorrinuH,  in  which  the  right  posterior  radial 
is  compound,  and  its  two  plates  are  in  line  vertically.  This  genus  is  an 
intermediate  form  between  the  earlier  and  later  Fistulata,  and  its  struc- 
ture throws  important  light  upon  the  phylogeny  of  the  group,  especially 
as  to  the  anal  plates.  Contrary  to  the  rule  in  most  of  the  earlier  Fistulata, 
the  plate  x  is  well  represented,  but  the  inferradi.il,  R,  is  not  in  a  position  to 
perforin  anal  functions. 

Let  us  examine  the  form  represented  by  Dcndrocrinus  Casei,  from  the 
Loner  Silurian  of  America  (Fig.  18),  a  species  with  rather  narrow,  horse- 
shoe shaped  radial  facets,  and  an  extremely  large  ventral  sac.  The  two 
posterior  radials  are  widely  separated,  and  the  plate  x  is  succeeded,  as  in 
Cyathocrinns,  by  three  plate.s,  t,  t,  t,  of  which  the  middle  one  rests  upon  the 


Revision,  Pt.  1.,  p.  05. 


MORPHOLOGICAL  PART. 


129 


triincixte  upper  face  of  plate  x.  The  pliite  to  the  right  lies  at  a  soinowhnt 
higher  level  than  the  one  to  the  left,  anil  does  not  toiicli  ,r,  owing  to  the 
greater  length  of  the  conipounil  radial,  while  that  to  the  left  toiicheH  it 
slightly.  The  three  plate.s  form  part  of  the  free  tube,  and  eaeh  one  is  fol- 
lowed by  a  vertieal  row  of  other  tube  plates. 

Comparing  this  strueture  with  that  of  Iltttrorr'mus  (Fig.  10),  Evtmocrbnts 
(Fig.  11),  and  Ifybocrliuin  (Fig.  8),  we  find  tiiat  tlio  plate  t  in  all  these  forms 
takes  practically  the  place  of  the  tiirce  plates  (ttt)  in  Ikitilriirr'nutn.  In 
either  case  the  plates  constitute  the  lower  tube  plates,  and  rest  —  the  one 
as  well  as  the  three  —  upon  the  sloping  upper  faces  of  the  two  posterior 
radials;  but  while  the  three  plates  of  jDt'Hf//'ocr»u<s  ore  supported  by  a  special 
anal  plate,  the  radials  of  Ifrfirocrinus,  etc.,  meet  underneath,  and  the  anal  is 
unrepresented.  In  Dcndrorrhms,  which  has  an  extremely  large  anal  tube, 
the  anal  x  is  well  represented  ;  while  in  the  three  other  genera,  in  which  the 
tube  is  narrow,  and  the  outer  edges  of  the  radials  are  sufficient  to  support 
it,  that  plate  is  wanting.  If  it  were  true  that  the  plate  t  in  Jlctcrocriinis 
represents  the  plate  x;  and  sunk  down  in  palafozojc  times  to  the  basals,  as 
supposed  by  Bather,  the  plate  x  would  be  represented  twice  in  Dcndrocriniis 
Casci,  once  by  x,  and  again  by  f,  both  plates  being  present  and  in  place. 

Bather  makes  the  statement  (p.  331)  that  the  "  brachianal  "  and  the 
plates  succeeding  it  in  regular  series,  are  to  be  regarded  as  brachials,  but 
that  the  remaining  plates  of  the  sac  are  nothing  more  than  plates  deposited 
in  an  extension  of  the  ventral  perisome,  and  in  conformity  with  this  he 
has  called  the  superradial  of  locrinits  an  axillary  plate.  The  term  "  axillary  " 
in  Crinoid  terminology  is  given  exclusively  to  jilates  of  the  ra3's,  and  every 
axillary  is  followed  necessarily  by  a  branching  of  the  arm.  Bather  in  using 
that  term  must  have  supposed  that  the  so-called  brachianal,  and  the  plates 
succeeding  it,  are  parts  of  a  modified  arm,  which  in  geological  time  became 
incorporated  into  the  sac,  for  in  no  other  way  could  we  understand  why  lie 
called  it  an  axillary.  He  has  probably  been  misled  by  the  angularity  which 
occurs  upon  the  upper  face  of  the  superradial,  or  by  the  form  of  the  plates 
succeeding  it  to  the  left,  and  the  slanting  position  of  the  posterior  arm  to  the 
right.  In  that  case  he  overlooked  that  the  radials  in  Adinocrinns  also  have 
sloping  upper  faces,  and  yet  that  those  plates  are  not  axillaries,  supporting 
as  they  do  at  one  side  a  costal,  but  an  interbrachial  at  the  opposite  side ; 
and  it  did  not  occur  to  him  that  such  might  be  the  case  also  in  Jocrimis. 
Examining  the  anal  interradius  as  it  appears  in  the  Camerata  among  the 

17 


ki 


130 


TlIK  CHINOIDKA  CAMKRATA  OF  NORTH   AMKRICA. 


Vftrioiis  familii'fl,  we  find  in  tlio  Biitociinitliv)  directly  above  the  plute  a;  a 
Huppleiiifiitiiry  mud,  mid  an  interbrachial  at  cat-li  wide  of  it,  exactly  as  in 
most  tpccies  of  Cyuthovrinus  and  DeiidrDcrhuia,  except  that  the  interbrachials 
of  the  two  latter  —  /'.  c,  the  plates  corresponding  to  them  —  are  incorporated 
into  tho  tube,  but  those  of  the  Batocrinidoo  into  the  cup.  Turning  to  the 
Actinocrinidie,  the  plate  ,c  supports  a  supplementary  anal  in  the  second  inter- 
brachial row,  but  none  in  the  first,  a  structure  recurring  in  Gni/iliiocriniis, 
in  which  a;  is  followed  by  two  tube  plates  which  take  the  place  of  the  two 
interbrachials  of  Actinocrinus.  In  the  Dolatocrinites,  however,  in  which  x  is 
wanting,  and  the  first  row  of  the  anid  interradius  is  formed  of  n  single  plate, 
this  rests  upon  the  sloping  faces  of  two  radials,  tins  occupying  almost  the 
same  position  as  the  plate  /  {:v  of  Bather)  in  Edcnocrinus,  Ili/hocrinufi,  and 
lucrinus.  That  the  plate  t  in  some  of  these  forms  is  somewhat  irregular  in 
position,  leaning  more  to  the  right  than  to  the  left,  is  due  to  the  asymmetry 
of  the  right  posterior  radial. 

From  these  observations  it  appears  that  there  is  a  close  agreement  be- 
tween the  anal  i)late  and  tube  plates  of  the  Fistulata  on  one  side,  and  the 
anal  plate  and  interbrachials  in  the  cup  of  the  Camerata  on  the  other;  and 
we  are  led  to  believe  that  those  plates  respectively  are  homologous.  Admit- 
ting this,  wo  have  a  much  more  satisfactory  explanation  of  the  anal  plates  of 
the  Fistulata  than  that  given  by  Bather,  whose  views  are  totally  at  variance 
with  the  structure  of  the  Camerata,  and  are  based  upon  premises  which  are, 
to  say  the  least,  hypothetical. 

After  agreeing  upon  the  structure  of  Dendrocrimts  and  locrimts,  that  of 
the  other  Fistulata  is  readily  understood.  Ammcdocrinus  is  in  a  condition 
similar  to  that  of  locrinus,  but  it  has  two  compound  radials  instead  of  one 
(Fig.  12).  The  plate  x  is  unrepresented,  and  the  tube,  which  is  narrow, 
rests  within  a  notch  formed  by  the  sloping  upper  faces  of  the  two  posterior 
radials.  Nearly  the  same  structure  is  found  in  Heterocrimis  and  Edenocrbnts 
with  thi-ee  compound  radials,  and  in  ILjhocrinus  with  but  one,  and  in  all  of 
them  the  plate  a;  is  wanting.  IIo»v  Mr.  Bather  could  conclude  from  the 
structure  of  Edenocrimts,  locrimts  or  nyhocrimis,  three  of  the  most  primitive 
forms,  that  x  originated  as  a  plate  "■  morphologically  correspomling  to  an 
ordinary  brachial,"  and  that  t  could  sink  down  to  the  basals,  we  do  not 
understand.  It  appears  from  his  own  diagram  that  the  plate  which  he  calls 
X  in  Edenocrinus  is  placed  symmetrically  between  the  two  posterior  radials, 
resting  as  much  on  the  one  plate  as  on  the  other,  but  not  touching  the  basals. 


QQQTa  0 


mm^ 


MORPnOLO(iI(  Al.   PART. 

TABLE  C. 


131 


^ 


A 


D^fe^ 


14 


1S|     oTo^ol^ 


m" 


my 


^^ci»2>c%o.o 


^S^^ 


DIAGli.VMS    ILLUSTRATING    THE  CHANGKS    IN    TIIK    DEVELOPMKNT   OE  THE  ANAL 

SIDE  IN  THE  INADLNATA. 

1.  lon-imi.i  si(brra.i.iiis  ;  2.  Pu/morriiiiis ;  3.   Ci/allmTimis ;  4   Pisorriiiiis  ;  5    Ildphi-riiim  rlio ;  fi.  St/m. 
bathocniiiis ;  7.   linerorriiiin  ;  H.  N^//ocriiiii.i ;  i).  loi-riiiiix  ;   10.  Helcrorriniis  helli'villciisii ;  11.  Erlrnocriiius ; 
12.  Aiiowaloniniis  ;  \X  noiiiocriiim ;  U.  Dendroerinus ;  \o.  Poterioeriiiiis ;  16.  Crriocriiiiis ;  17.  Ulocrinut ; 
18.  Erisoeriiim ;   19.  Alliigecimin. 
*  =  bnsal3;  «  =  ra(liiils;  /f'  =  iiiferrailinl;  .r  =  special  nnnl  plate ;  /=costals;  /  =  tiibopktes ;  o=orals. 


M 


^ 


132 


TIIK   CHINOIDKA    (  AMKIIATA   OK   NOKTII    AMKKICA. 


Seo  mir  diagriiiM  (Fig.  11).  So  nl.so  (Iio  pliitc  /  of  Ifctrrocriiiits  hclltrillcHsis 
(Fig.  10),  llioiijfli  loMH  syimnotriciilly  (li.><|i().soil,  whU  inmii  Liolli  ruUiul!*,  iiiitl 
nut  on  tliu  pliitu  tu  the  right  only,  nn  (igiirud  hy  Hiitlu-r. 

Wo  now  pii.ss  to  tlioso  forms  in  wliicli  the  inrcrmdiiil  II'  pcrfoniiH  the 
function.'*  of  an  iinul  plate.  The  first  stop  in  this  direction  it*  nhown  by 
Ilonincrlinis  (V\g.  14),  lliifri/dcriiiii.i,  Oncocriiiiis,  iind  liitnjrrlnuH,  in  whicli  (lie 
Huperriidial  A'  ha.s  siiifted  .slightly  to  the  light,  and  it*  connected  with  the 
inferriidiivl  hy  an  oblique  sutiu-e  ;  contrary  to  the  caHO  of  I)cii)lrocriiius, 
in  which  the  two  plates  are  arranged  vertically  (Fig.  13).  The  plate  t  in 
tho.so  forms  rests  upon  R  without  touching  If,  and  the  plato  x,  which  is 
comparatively  largo,  rests  against  botli  sections  of  the  compound  radial. 

Bather  explains  the  evolution  that  took  place  in  these  forms  by  "  the 
shifting  of  the  radianal,"  and  that  "./•  has  sunk  still  lower  into  the  dorsal 
cup,  and  is  now  on  a  line  with  the  radials."  Nothing  of  this  kind  is  indicated 
by  the  specimens,  which  clearly  show  that  tlio  radianal  throughout  the 
Fistulata  retains  the  same  position,  whether  it  constitutes  a  part  of  the  radial 
or  .serves  as  anal  plate.  It  oidy  changes  its  outlines  so  as  to  conform  to  the 
shape  of  contiguous  plates.  As  the  tube  became  larger,  the  radinis  spread 
out,  and  the  vacant  space  thus  formed  was  filled  by  a  new  plate,  a;.  There 
was  no  sinking  of  the  plate  t,  which  never  moved  from  its  place  above  the 
radials. 

Another  stage  in  the  developmental  history  of  the  anal  area  among  the 
Fistulata  is  presented  by  P(irlsorriaiin,  Atchstorriniis.  EuKpirocrinuH,  and  the 
typical  PoteriocriniiliB.  Bather,  in  alluding  to  them,  makes  the  following 
statement:  "  In  the  Poteriocrinites  (see  our  diagram  Fig.  2)  another  change 
has  taken  place;  the  radianal  has  passed  through  a  revolution  of  90°,  and  the 
lowest  plate  of  the  ventral  .sac  {t)  has  sunk  down  between  R  and  .r."  If  we 
understand  what  this  means,  he  assumes  that  the  lower  section  of  the  radial 
moved  to  the  left ;  while  in  fact,  as  the  specimens  show,  it  was  the  upper 
section  of  the  plate  that  moved  away,  shifting  to  the  right  and  leaving 
a  space  for  R'  and  t  to  meet.  Thus  it  was  that  x  came  to  rest  against  R', 
but  not  against  7?,  from  which  it  was  separated  by  the  plate  /.  An  increase 
of  width  in  the  anal  area  became  necessary,  as  the  surface  for  the  support  of 
the  tube  was  insufficient  to  hold  it.  In  Homocrinus  and  Dendrocrimis,  the 
costals  occupy  only  a  comparatively  small  part  of  the  radial,  and  a  rather 
large  portion  of  the  latter  serves  as  a  support  for  the  tube.  In  the  Poterio- 
crinidae,  however,  and  in  Parisocrinus,  Enspirocrinus,  and  Atelestocnnus,  in 


MOKI'IIOLOdlfAL   I'AUT. 


133 


which  thu  hracliiiilH  fill  up  tliu  giviiter  imrt,  ur  nil  of  tliu  diMlul  luci*  uf  the 
nidiiilH,  It  I'utiuii'fd  udditiutitil  HuifucuH  for  thu  iiccomiuudutioii  ut'  the  laigi' 
tiihe. 

From  the  stnictiiro  of  the  typiciil  Potoriocriiiidro  w«  coinp  to  thnt  of 
Vliirriiiiin,  (I'rdjiltiiiiriiiiis,  C'lriiirriiiiis,  Krisurrlims,  uml  StinDiiuturriiuis,  wliicii 
wo  rej^iii'd  a^  tniiHilioii  I'oinis  toward  h'urrliuis.  'I'lio  vt'iilral  tula',  which  in 
the  latter  of  thoHu  foriiiH  dwindled  to  a  Hliort  cone,  did  not  roqtiire  ns  largo  ii 
Hnpport  in  the  dornal  cnp,  iind  nH  the  nnal  p'litCH  gradually  hecaine  oh.xolote, 
tho  posterior  radiaN  resumed  u  Hymmetriial  form.  In  Ulocriniis  {V\\^.  17) 
the  plate  x  was  crowded  out  by  the  large  nidinnal ;  while  in  Oia/i/iiocrimis 
and  Ccn'iicrliiiis  (Fig.  10)  only  tho  former  ix  ro[trcsented.  In  (Iriipliincriitiis, 
with  a  wide  ventral  Mac,  tho  anal  plate  ih  large;  in  Ccn'ocrintis  it  is  reduced 
to  a  small  piece,  and  the  posterior  bnsal  is  con.siilerahly  elongated.  JCrisit- 
ci'iiws  (¥\g.  18),  S/fiiiiiKiiocfinus,  and  Eiicrintis  have  no  anal  plates  at  all.  the 
cup  being  perfectly  synnnotrical ;  and  the  tube  rests  entirely  upon  the 
edges  of  the  radials,  whence  it  started  in  Hi/f'nrrimm,  Eclcuocriiius,  and 
allied  forms. 

In  view  of  these  facts,  it  see.ns  lo  us  that  Bather's  theory  of  a  "  brachi- 
anal"  is  based  upon  a  wrong  interpretation  of  some  of  tho  plates.  If  it 
were  true  that  tho  plato  of  Incriniis  to  the  left  of  the  supraradial  passed 
down  in  later  forms  to  the  basals,  it  would  mean  nothing  less  than  a  partial 
revolution  of  tho  entire  tube.  This,  however,  is  dispioved  by  the  structure  iis 
well  as  tho  palaeoutological  development  of  the  tube,  which  latter  is  genendly 
composed  of  lon;jitudinal  rows  of  hc.vangular  pieces,  alternating  in  adjoining 
rows.  In  the  earlier  and  simpler  forms  tho  tube  consists  of  only  five  series, 
one  to  each  intorradius,  that  of  tho  nnal  side  resting  upon  plate  /.  Later  on, 
as  tho  tube  grew  larger,  a  now  row  of  plates  was  introduced  with  plate  .<•  sup- 
porting it.  When  there  are  three  series,  as  in  Detxhnrrhnis,  the  third  genendly 
rests  upon  one  side  of  tho  left  posterior  radial.  The  arrangement  of  the 
plates  within  tho  rows  is  .so  regular  that  if  a  sinking  of  the  plate  t  bad  taken 
place,  it  would  certainly  be  indicated  by  some  disturbance  among  the  lower 
plates  in  the  tube.  In  species  where  tho  tube  has  more  than  three  rows,  one 
or  more  of  tho  primar}'  rows  dichotomize  at  some  distance  from  the  cup. 
The  fact  that  the  increase  of  the  tube  pliylogenetically  took  place  by  the 
introduction  of  new  rows  of  plates,  is  a  strong  argument  in  favor  of  our  idea 
that  the  plate  x  is  also  a  supplementary  piece,  and  was  introduced  in  the 
same  manner  as  the  plates  which  it  supports. 


'    >|i 


? 


134 


THE  CRIXOIDKA   CAMERATA   OF   NOUTII   AMERICA. 


The  syininetry  of  the  Ciii  oitls,  as  a  rule,  is  bilateral,  and  the  nnal  area 
occupies  the  median  axis.  The  usyniniotry  which  occurs  in  many  Fistulata, 
and  in  certain  Ichthyocrinidiu,  is  caused  by  irregularities  in  the  radials. 
Wherever  tiiese  attain  a  regular  form,  the  plate  x  takes  its  median  position, 
and  the  plates  ol'  tiie  ventral  tube  are  arranged  on  a  strictly  bilateral  plan. 

Wiiether  the  symmetrical  calyx,  as  represented  in  the  Silurian  and  later 
Cyatliocrinidic,  was  evolved  from  the  asynnnetrical  form,  we  are  unable  to 
ascertain.  It  may  be  that  tiie  two  had  a  common  synnnetrical  ancestor,  or 
tliat  ail  these  Crinoids  were  primitively  asynnnetrical,  and  that  the  lower 
section  of  the  posterior  radial  became  early  resorbed  in  some  cases.  Against 
the  former  theory  it  may  be  said  that  in  the  Lower  Silurian  Fistulata,  so  far 
as  we  know  without  exception,  the  right  posterior  nidial  is  compound,  and 
that  the  synnnetrical  form  occurs  with  the  other  in  the  same  families;  against 
the  latter,  that  the  symmetrical  form  is  already  well  represented  in  the 
Upper  Silurian. 

We  have  made  no  reference  here  to  the  Calccocrinidro  and  Catillocrinidoe, 
as  we  have  not  at  present  the  material  to  study  the  older  forms;  but  we  feel 
quite  certain  that  their  structure  in  this  respect  shows  no  material  departure 
from  that  of  the  older  Fistulata. 

The  anus  of  the  Crinoids  is  located  in  the  disk,  and  is  either  central,  sub- 
central,  or  marginal,  —  in  the  latter  case  .sometimes  coming  down  to  the 
arm  region.  In  some  species  there  is  merely  a  simple  opening  passing  out 
directly  through  the  disk  ;  others  have  a  tul)e  with  an  opening  at  the  distal 
end  or  along  the  side.  Tlie  size  of  the  tube  is  quite  variable.  In  some 
genera  it  rises  to  a  height  of  several  inches  beyond  the  arms ;  while  in 
others  it  is  less  tlian  half  their  length.  The  tube  is  compo.sed  of  heavy, 
generally  nodose,  wedgeform  pieces,  admitting  but  little  mobility  in  the 
structure.  When  there  is  no  tube,  the  amis  is  generally  situated  within  the 
centre  of  a  wart-like  intlation,  composed  of  very  minute  pieces,  which 
possibly  were  movable,  and  could  be  drawn  in  by  the  animal,  like  those 
in  the  "  probo.scis"  of  recent  Crinoids,  so  as  to  open  or  close  the  aperture. 

Tliere  has  been  some  difference  of  opinion  whether  or  not  species  with 
an  anal  tube  should  be  separated  generically  from  those  with  a  simple 
opening.  Considering  the  slight  differences  upon  Avhicli  many  genera  have 
been  founded,  it  would  seem  that  the  tubular  structure  ought  to  be  of 
sufficient  importance  to  justif^v  a  separation  :  but  considering  that  various 
groups,  after  being  carefully  restricted  with  reference  to  all  other  characters, 


MORPHOLOGICAL   PART. 


13o 


include  both  forms,  its  viilue  as  a  full  generic  cliaractor  might  well  be 
doubted.  It  was  probably  this  that  led  Meek  and  Worthen  to  establish 
subgenera  for  these  forms.  We  finally  concluded  to  make  them  full  genera, 
finding  considerable  objection  among  naturalists  to  subgeneric  divisions. 
Only  in  Flatycrinus  and  Mdocriims  were  we  obliged  to  retain  both  forms 
under  the  same  generic  name,  as  we  are  unable  to  separate  them.  Their 
tegmens  are  rarely  preserved,  and  among  the  species  of  Platijcrmus  espe- 
cially are  found  all  possible  gradations  from  a  simple  opening  to  a  good 
sized  tube. 

As  a  rule,  a  tube  occurs  more  frequently  among  species  in  which  the 
arms  form  a  continuous  series  around  tiie  calyx;  while  species  in  which  they 
are  arranged  in  clusters  often  have  a  simple  opening.  Most  of  the  latter 
forms  have  a  wide,  more  or  less  depressed  space  along  tiie  disk,  between  the 
two  posterior  rays,  for  the  foecal  matter  to  pass  out;  but  when  the  tube  is 
long,  and  the  arms  in  close  contact  all  around,  the  excretions  were  dis- 
charged above  the  arms. 

Occasionally,  among  species  with  a  slender  tube,  we  find  specimens  in 
which  during  the  life  of  tiie  animal  the  tube  was  broken  at  the  base,  and 
the  fractured  edges  upon  the  disk  were  rounded  off  by  calcareous  growth, 
so  that  it  appears  like  a  simple  opening.  From  this  we  ooiiclude  that  the 
tube  had  no  important  bearing  upon  the  general  organization  of  the  animal, 
and  that  tlie  Crinoid  could  live  without  it.  This  is  also  indicated  by  speci- 
mens in  which  the  anal  tube  was  obstructed,  and  a  new  passage  formed 
at  another  place.  Abnormal  passages  of  this  kind  occur  along  the  tube, 
upon  the  disk,  within  the  dorsal  cup,  and  even  within  the  basal  ring. 
They  are  more  or  less  restricted  to  the  posterior  side,  but  are  not  neces- 
sarily in  a  vertical  line  with  the  anus,  as  wc  formerly  supposed.  When 
it  occurs  within  the  basal  ring,  the  opening  is  located  anteriorly,  but 
turns  to  the  right  whenever  it  enters  the  sides  of  the  dorsal  cup.  It  is 
located  posteriorly  —  or  nearly  .so  —  close  to  the  arm  bases,  but  above  the 
calyx  it  may  occur  on  any  side  of  the  tube.  The  Museum  of  Comparative 
Zoology  has  a  very  interesting  specimen  of  Bniocrimis  lonr/irosiris,  in  which 
a  new  tube  of  the  same  size  as  the  original  one  has  been  formed  just 
above  the  calyx.  In  this  instance  apparentU'  the  second  tube  also  became 
obstructed,  and  a  third  one  was  in  process  of  formation.  A  similar  casi-  is 
presented  by  our  specimen  of  Bntocrhum  hmra  (Plate  IV.,  Fig.  14).  The 
tube  in  the  specimen  of  Eiitrochocrinus  Christi/i  (Plate  IV.,  Fig,  10)  gives  off 


■  [i 


136 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


a  small  branch  horizontally  at  a  short  distance  from  the  disk.  In  another 
specimen  of  that  species  (Plate  IV.  Fig.  17),  in  which  the  tube  is  broken  above 
the  arms,  it  was  replaced  by  another,  which  starts  off  !*oiaewhat  obliquely 
from  the  top  of  the  stump.  A  tube  in  a  similar  condition  was  observed  in 
a  specinu'U  of  Lobocrinus  2))jr)furmis,  but  there  tiie  recuperation  made  but 
little  progress,  for  the  new  part  did  not  attain  one  third  the  width  of  the 
old  tube  at  the  point  of  fracture.  In  the  specimen  of  Macrocrinus  jticundus 
(Plate  IV.  Fig.  15),  a  small  branch  .starts  from  the  tube  close  to  the  calyx, 
while  in  another  specimen  of  our  collection  a  braneiilet  is  given  off  near  the 
end  of  the  tube.  In  Fig.  12  of  the  same  plate  (Steijanocnmts  pentagomis), 
and  in  Fig.  11  {Teleiocrinus  unihrosus)  a  second  tube  was  formed  at  the  top 
of  the  disk,  iu  the  former  occupying  the  median  line  of  the  posterior  area, 
and  in  the  latter  directed  .sliglitly  to  the  right.  In  the  remarkable  specimen 
oi  Etifrochocrimis  Christi/i  (Vhxte  IV.  Fig.  13)  all  the  arms  of  the  right  pos- 
terior ray,  and  the  outer  arm  of  both  adjoining  rays,  were  destroyed,  and  the 
break  in  the  test  was  closed  by  irregular  new  {/.ates,  which  support  a  con- 
spicuous second  tube.  A  still  more  remarkable  instance  of  recuperation  is 
presented  by  a  specimen  of  Batocnmtn  stthwqitaHs  (Plate  IV.  Fig.  10),  in  which 
an  enormous  tube  breaks  forth  above  the  basals.  It  occupies  the  whole 
length  of  the  dorsal  cup,  and  involves  the  plates  of  the  posterior  interradius, 
as  well  as  of  the  posterior  ray,  and  even  some  of  the  arm  openings.  The 
plates  bulge  outward  almost  at  right  angles  to  the  sides  of  the  cup,  and  form 
tiiu  lower  part  of  tlio  tube.  Fig.  9  has  a  very  large  opening  between  the 
basals  leaning  somewhat  toward  the  anterior  side,  which  we  think  performed 
the  functions  of  the  anus  in  that  specimen. 

Passing  now  to  the  Inadunata  Larviformia,  it  must  be  stated  that,  so  far 
as  observed,  the  anal  x  is  unrepresented  throughout  this  group  (.see  Figs.  4, 
5,  6,  and  19  of  the  preceding  diagrams),  nnd  we  know  of  no  case  in  which  the 
anal  tube,  where  it  exists,  is  supported  by  an  iuferradial.  This  is  explained 
by  the  absence  of  interbraohial  and  intcrambulaor.il  plates,  and  the  position 
of  the  anus  intermediate  between  the  radials  and  orals,  or  piercing  the  latter. 
risocrinus*  Phimocrinus,  and  Symbathocrimts  have  a  long  slender  tube  be- 

•  The  tube  of  Pitorrimit  wns  observed  by  Bntlier,  niid  described  by  him  in  liis  late  work  on  "The 
Oriiioidca  of  Gollnnd,"  Part  I.  p.  22).  Tt  rests  upon  the  triiiieatcd  limbs  of  the  eompoinid  mdial  and  the 
large  simple  one  to  the  left ;  hut  not  upon  the  t\ro  supported  by  the  plate  R'.  Halher  refers  the  proximal 
plate  of  the  tube  to  the  nnnl  .r,  allhoui;h  the  plate  rests,  like  /  in  Kr/riioi-n«uf  and  ffy/jofiimif,  upon  the 
radials,  anil  lakes  no  part  in  tlie  eompnsilion  of  the  eup.  So  also  tlie  eorrcsponding  plate  in  Symhathocriimi 
is  a  tube  plate,  and  not  an  anal  as  we  stated  in  our  earlier  writings. 


% 


MORPHOLOGICAL  PART. 


137 


I        I 


tween  the  arms  to  their  full  length,  which  in  Si/nibathocnmis  is  composed  of 
elongate  quadrangular  pieces.  The  tube  rests  upon  the  upper  faces  of  the 
posterior  radials,  and  extends  to  the  tips  of  the  arms.  ILqdocrbms,  as  we 
understand  it,  has  a  simple  anal  opening,  piercing  the  upper  half  of  the 
posterior  oral.  Ciipressovrimts  has  a  well-defined  aperture  between  the 
muscle  plates  of  two  adjoining  radials. 

The  anus  of  the  Inadunata  Fistulata  has  been  observed  in  but  a  few 
instances,  and  then  only  in  the  CjiUliocrinida!,  the  Poteriocrinidaj,  and  in 
the  embryonic  Ilijhocrinus  and  Carabucrlniis,  In  all  of  these  cases,  the  open- 
ing was  apparently  covered  by  a  rather  large,  rounded  pyramid  of  eight  or 
more  pieces,  which  reseiiibles  the  anal  pyramid  in  the  Cystids.  In  Caraho- 
crimcs,  in  which  the  ventral  disk  remains  permanently  in  the  larval  state, 


n 


(    i' 


Fio.  1. 


Fig.  2. 


Carabocriiiiis. — Fig.  1.  Ventral  Hspect.  Fig.  2.  Dorsal  aspect. 

R  =  rnilinls ;  IV  =  nuliaiiiil ;  x  =  anal ;  rp  =  nnal  pyramid ;  o  =  orals. 

having  five  large  orals  similar  to  those  of  the  Larviformia,  and  snbtegminal 
ambulacra,  the  pyramid  is  excentric  and  directed  upwards  (Figs.  1  and  2  of 
the  accompanying  diagrams).*  A  similar  anus  was  observed  by  W.  R.  Billings 
in  Hyhocrimis  conicus.  In  Cyathocrimis  wo  have  observed  the  anal  pyramid 
in  several  species,  and  found  it  located  in  all  of  them  at  the  end  of  tlie  tube, 
directed  anteriorly  (Plate  VII.  Figs.  11  <ih  rnd  \2(if/).  The  anus  of  the  Pote- 
riocrinidoB,  which  we  havf;  seen  in  Poteriocrinu.t,  Decadncrinns,  and  in  several 
species  of  Sei/talocrimis  and  Scrq^hiocrinus,  is  located  at  some  distance  from 
the  top  of  the  ventral  sac,  and  invariably  at  the  anterior  side,  sometimes 

•  These  diagrams  were  made  after  drawings  hy  Mr.  Waller  R.  Billings.    The  specimen  of  Fig.  1  is  in 
the  collection  of  Mr.  J.  Stewart,  that  of  Fig.  2  in  his  own  collection. 

18 


138 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


very  low  down  in  the  sac  (Plate  VII.  Fij^.  la).  An  nnitl  pyramid  has  never 
been  fomul  in  place  in  this  family,  but  that  it  existed,  at  k-a.st  in  some  of  the 
species,  seems  very  probable  from  the  form  and  large  size  of  the  opening 
(Plate  VII.  Figs.  1  a,  2a, h,  3,  4,  7,  8).  There  are  other  Poteriocrinidio,  and 
espL>cially  among  .species  with  an  inllated,  balloon-shaped  sac,  which  have  no 
openings  in  the  sac,  and  we  are  inclined  to  suppose  that  in  these  cases,  and 
also  in  many  other  Fistulata,  the  anus  was  located  in  the  di.sk  proper  between 
the  sac  and  tlic  mouth.  In  the  remarkable  AuIocrii)Hs  represented  on  Plate 
VII.  Fig.  9,  there  is  a  large  spout-like  tube  passing  out  from  the  huge  sac 
between  the  arms  on  the  anterior  side,  half  way  down,  like  the  simple 
opening  in  Figs.  7  and  8.  We  have  found  this  extraordinary  tube  pre- 
served in  five  other  specimens  of  this  species,  and  its  form  and  position 
are  very  constant. 

The  anus  of  the  IchthyocrinidaB  has  been  observed  only  in  Taxocrinus  and 
OnycJwcrimis  {Forbesiocriiius  de  Kon.  andLe  Hon).  Both  genera  have  a  small 
tube,  of  which  the  posterior  side  consists  of  a  vertical  row  of  subcjuadran- 
gular,  comparatively  large  plates.  I*s  anterior  side  is  composed  of  a  large 
number  of  very  minute  pieces,  forming  a  kind  of  pouch,  widest  at  the 
proximal  end,  which  gradually  pas.ses  into  the  di.sk.  At  the  anterior  side 
the  tube  leans  considerably  to  the  right,  and  it  may  be  suggested  from  this 
that  Taxocrimis  ami  Onychocrhms  are  derived  from  the  asynunetrical  Gnori- 
mocrinus,  whicii  apparently  had  a  similar  tube.  The  arrangement  of  the 
anal  plates  in  the  Iciitliyocrinida!  is  substantially  the  same  as  in  the  Fistu- 
lata. In  some  of  their  genera  only  the  plate  ,t  is  represented,  in  others  IV ; 
while  still  others  have  no  anal  plate  at  all.  Bather  makes  no  rei'erencc  to 
the  anal  plates  of  the  Ichthyocrinidoo,  but  regards  tiie  anals  of  the  Camerata 
as  morphologically  distinct  from  those  of  the  Fistulata.  On  ]iago  31i) 
{op.  cit.)  he  says:  "it  may  be  pointed  out  that,  as  interradials  do  not 
enter  into  the  composition  of  the  dorsal  cup  in  an^^  Fistulata,  none  of 
these  plates  can  well  be  the  homolognes  of  interradials  :  in  many  of  the 
Camerata  actual  interradials  ai'e  present  in  the  anal  area,  b>it  in  the  Fis- 
tulata at  least  we  must  look  elsewhere  for  tlie  origin  of  the  so-called 
'  anal '  plates."  Now  if  it  is  true  that  the  anals  of  the  Camerata  re- 
present something  different  from  those  of  the  Fistulata,  because  the}' 
possess  no  interbrachials,  it  must  be  the  same  also  with  the  anals  of  the 
IchthyocrinidaB,  among  whicii  interbrachials  are  represented.  But  what 
would  be  the  result?    Some  of  their  genera  have  interbrachial  plates,  and 


. 


! 


MORPHOLOGICAL  PART. 


139 


others  not.  In  Ljcannrrlnus  IJilliiujsi*  tliere  is  iit  the  posterior  side  an  niiiil 
a;,  togetlior  with  a  rudiaiial ;  while  at  tiie  other  four  sides  the  radials  and 
costals  of  a<ljoining  rays  meet  hitcrally.  Lccanocrinus  macropdulus  Angelin 
(not  nall),t  on  tiie  other  hand,  with  exactly  the  same  arrangement  of  anal 
plates,  has  a  large  interbrachial  plate  at  the  four  regular  sides.  The  case  is 
even  more  perplexing  in  Taxocrbnis  Thicniei,  of  which  some  specimens  have 
one  or  three  interbrachials,  while  others  have  none.  We  thus  find  within 
the  same  genus,  and  even  within  the  liuiitsof  the  same  species,  interbrachials 
present  or  absent,  and  according  to  Bather's  theory  the  anal  plates  of  one 
specimen  would  be  homologous  with  the  anals  of  the  Fistulata,  and  those  of 
the  other  structurally  distinct.  He  seems  to  have  regarded  the  anal  plate 
in  the  larva  of  Anfedun  as  the  homologue  of  the  plate  x  in  the  Fistulata, 
because  the  genus  has  no  interbrachials.  lie  says:  "  it  is  not  an  interradial ; 
for  the  so-called  '  interiadials '  that  some  ob.servers  claim  to  have  seen  are 
only  perisomic  plates  of  no  morphological  importance ;  further  it  is  a  most 
gratuitou'<  assuuiption  to  make  Antedon  the  oidy  form  with  an  interradial  in 
the  anal  area,  while  devoid  of  true  interradials  in  the  otlier  interradii."  In 
assuming  that  Antedon  has  no  interradials,  he  employs  the  term  in  the 
narrow  sense  in  which  it  has  been  used  heretofore ;  but  since  then  we  liave 
learned  that  all  i)lates  interposed  between  the  rays  and  the  ambulacra  con- 
stitute parts  of  the  same  element,  and  the  same  plates  morphologically  may 
be  interbrachial  in  one  group,  and  partly  or  wholly  interambulacral  in 
anotlier. 

Thaumntocrinus  is  the  only  recent  genns  which  lias  a  tube,  such  as  we 
find  among  the  PalaBocrinoidea.  This  tube  rests  upon  a  large  interradial 
plate,  which,  however,  is  not  a  special  annl,  for  a  similar  plate  is  interposed 
between  the  radials  of  the  other  four  sides,  exactly  as  in  the  Rhodocrinidce. 
This  seems  to  us  a  further  proof  that  the  plate  x  is  not  a  primary  element, 
but  a  supplementary  plate,  and  was  introduced  only  in  cases  where  the 
structure  of  the  anus  required  it. 

•  Iconogr.  Crin  Suec,  PI.  XXIL  Fig.  25. 
t  Ibid.,  PI.  XIX.  Fig.  4 


ill 


n 


M 


140 


TIIK  ClUXOIDEA  CAMKRATA  OF  NORTH  AMKRICA. 


INTERNAL  CAVITY  OF  THE  CALYX. 

A.     Tlic  Chambered  Organ  and  the  Axial  Canals. 

A  striking  feature  in  the  organization  of  the  Comatuloo  is  tiie  quinquclo- 
cular  organ,  situated  in  the  cavity  of  the  ceiitrodcrsal,  and  phiced  at  right 
angles  witli  the  central  axis.  Tiiis  organ  was  first  noticed  by  Ileusingor, 
who  in  1828  described  it  as  the  central  organ  of  the  blood  vascular  .system. 
Mliller  also  took  it  to  be  a  heart-like  organ  in  connection  with  a  system 
of  membranous  tubes.  Dr.  W.  IJ.  Carpenter  regarded  the  membranous 
tubes  of  Mliller  as  solid  fibrillar  cords,  proceeding  from  a  similarly  con- 
stituted envelope  around  the  chambered  organ,  and  he  came  to  the  con- 
clusion that  this  fibrillar  sheath,  and  th>  cords  proceeding  from  it,  constitute 
the  central  nervous  system  of  the  Comatulu).  This  was  afterwards  confirmed 
by  experimental  evidence,  and  is  now  generally  admitted  by  zoiilogists. 

The  organ  in  question  is  a  sac,  divided  into  live  radial  compartments, 
enclosed  by  a  thick  envelope  in  connection  with  the  axial  cords.  From  the 
dorsal  surface  of  this  envelope  processes  are  given  off  to  the  cirri,  and  from 
its  margin  arise  interradially  five  short  primary  cords,  which,  passing  up- 
wards and  outwards,  bifurcate  into  right  and  left  branches  between  the 
centrodorsal  and  radials.  The  ten  secondary  cords  diverging  from  one 
another,  enter  the  substance  of  the  radials,  and  either  unite  in  pairs,  the 
right  branch  from  one  interradial  meeting  the  left  branch  from  the  adjoining 
one  (Figs.  3  and  4),  or  the  two  branches,  as  in  Enerinus  Uliiformk  (Fig.  5), 
without  touching  each  other,  proceed  on  separately  to  the  costals.  On 
reaching  the  first  axillaries  the  two  cords  open  out  into  two  branches,  right 
and  left,  and  after  traversing  the  plates,  enter  the  right  and  loft  arms, 
respectively.  In  addition  to  the  above  connections,  there  is  a  circular  or 
pentangular  commissure,  which,  immediately  after  entering  the  radials,  con- 
nects the  various  branches  among  themselves,  and  additional  connections 
between  the  branches  within  the  axillaries  supply  the  arms  (Figs.  3  to  4). 
The  axial  cords  along  the  arms  lie  in  tubular  channels  piercing  the  calcareous 
part  of  the  various  arm  joints,  each  cord  giving  off  alternately  right  and 
left  branches,  which  enter  the  pinnules. 

Chambered  organs  have  been  observed  also  in  Stalked  Crinoids,  but  the 
position  is  not  quite  the  same  as  in  the  Comatulae.     While  in  the  latter  the 


r 


MORPHOLOGICAL  PART. 


141 


orfan  is  lodged  within  the  centrodorsal,  and  is  covered  by  the  rosette,*  it  is 
in  rentacrinus,  which  has  no  centrodorsal,  contained  in  a  cavity  formed  by 
the  radiiils  above  and  the  basals  below.  The  five  chambers  of  Pentumnus 
are  not  closed  at  the  bottom,  but  are  continued  down  the  stem  as  five  vessels, 
systematically  arranged  around  a  central  axis.     These  vessels  were  regarded 


Fiii.  3, 


Fig    4. 


I 
i 


H 


:    I 


Fig.  5. 


i. 


Fig.  3,  position  of  tlio  axial  cords  in  tlie  yoniicr  AiiMnii  ronaeeiis  (after  W.  B.  Carpenter) ;  Fig.  4, 
their  position  in  tlie  atlult  (after  A.  M.  >[nrsliall)  ;  Fig.  5,  in  Eiirniim  /iHi/ormh  (after  Beyricli). 

ccl  =  centrodorsal ;  i  =  infrabasals ;  A  =  basals ;  R  =  radials.  Tlie  dark  lines  show  the  arrangement 
of  the  canals  in  tlie  dorsal  en  p.  '^ 

by  Dr.  P.  II.  Carpenter  as  homologous  with  the  five  openings  around  a  single 
one  on  the  underside  of  the  calyx,  and  along  the  stem  of  Ciipressncrinus,  Myr- 
tilocrinus,  and  Gasterocoma.     Among  recent  Stalked  Crinoids  a  chambered 

•  In  most  of  the  Comntulie,  the  embryonic  basals  are  metamorphosed  into  the  structure  known  as  the 
"  rosette,"  which  is  enclosed  within  the  radial  pentagon,  so  as  to  be  not  visible  externally. 


142 


rilE  CRINOIDKA  CAMERATA  OF  NORTH   AMERICA. 


;'S' 


organ  has  been  observed  in  lihizocrinitu,  JJat/ii/criniis,  nnd  Jlulojnm,  and  it 
existed  probably  in  the  other  genera.  Among  Jurassiu  and  hiter  fcssil 
Crinoids,  a.xial  canals,  piercing  the  body  of  the  calyx  plates,  are  known  to 
e.xist  in  the  Apiocrinidco  and  Engeniacrinida)  (Ilolopidie  Jaekol),  and  tliey 
are  readily  recognized  in  the  Tria.ssic  E)Krbms,  in  .some  of  the  later  Paia>o- 
zoic  Poteriocrinidiu,  and  in  Mijcovrbius  and  Cafillocrinus ;  but  wc  have  found 
no  trace  of  them  in  the  Camerata,  except  in  Stajannciinus  ])entagomis  (Plate 
LXI.  Fig.  3),  in  which,  so  far  as  observed,  the  five  or  six  proximal  plates  of 
their  tubular  appendages  are  pierced  by  a  canal.  Such  canals  occur  upon 
the  radials  in  some  of  the  Cyathocrinida*.  the  CuprcssocrinidiD  and  Gastero- 
comidiv,  and  we  may  suppose  that  a  chambcretl  organ  existed  in  these  and 
other  groups,  if  not  in  all  Crinoids.  In  cases  where  grooves  or  canals  for 
the  reception  of  cords  are  not  apparent,  the  cords  may  have  rested  against 
the  inner  wall  of  the  plates. 

B.     T/ie  Convoluted  On/an. 

In  the  abdominal  cavity  of  Palajozoic  Crinoids,  the  oidy  organic  structure 
tiiat  inider  very  favorable  conditions  has  been  observed,  is  a  peculiar  skeleton 
which  occupies  the  greater  part  of  the  cavity. 

It  is  a  large  convoluted  body,  in  its  outlines  resembling  the  shell  of 
a  Bulla,  open  at  both  ends.  Its  upper  part  rests  directly  beneath  the  origin 
of  the  ambulacra,  tiie  lower  end  within  the  baisal  ring  without  touching  the 
plates.  It  is  dilated  above,  contracted  below,  its  lateral  faces  jdaced  parallel 
to  the  inner  walls  of  the  calyx;  the  bottom  truncated.  In  some  .species  it  is 
subcylindrieal,  with  the  vertical  axis  the  longer,  in  others  globose  or  even 
depressed  globose.  In  coiling  around  its  axi.s,  the  partition  walls  do  not 
meet  each  other,  but  leave  more  or  Ie.s.s  wide  interspaces.  The  convolutions 
vary  in  numbtM'  from  2  to  4  according  to  species,  and  are,  as  they  pa.ss  out- 
ward, directed  from  right  to  left.  The  walls  in  the  usual  preservation  are 
thick,  and  perfectly  .solid,  as  they  were  descril)ed  by  Hall;  but  in  transverse 
sections  they  froquentl}'  appear  as  if  compo.sed  of  two  partitions  closely  fitted 
together,  and  closed  along  the  edges.  In  some  specimens,  however,  the 
walls  are  simple,  and  constructed  of  an  extremely  fine  and  delicate  filigree 
work,  composed  of  minute  pieces  or  bars,  with  intervening  meshes,  which 
do  not  intersect  at  any  uniform  angle,  but  anastomose  so  as  to  impart  a  kind 
of  irregular  regularity  to  the  form  and  size  of  the  meshes.  No  such  structure 
has  ever  been  observed  in  the  other  specimens,  in  which  the  pores  or  meshes 


MOHIMIOLOCI ICAL   I'XHV. 


14a 


seem  to  have  been  obncuifd  by  hoiivy  iiicrustiitioiiH  of  Milicious  iimttir  nt 
both  »iiiu.s,  and  thusu  iticruatiUiuiiM  iiiiiy  hiivu  piodiicud  tliu  aiipiueiit  diipU- 
cation  of  tijo  walls  (I'lato  V.  Figs.  1,  4,  'J,  and  12). 

Among  tho  many  buautii'ul  e.\ampk<s  in  tlio  Wachsniiith  collection  at  the 
Miist'iiin  of  Comparative  Zoology,  in  which  tho  convoluted  organ  is  pre- 
served, there  are  two  uni(iue  Kpecimens  (I'iate  V.  Fig.  11  and  Fig.  10);  the 
former  showing  the  delicate  porous  texture,  the  other  its  position  beneath 
the  anibulacral  skeleton.  The  collection  contains  also  the  remarkable  speci- 
men of  Mdcrocrimts  vcrnextiUanus  (Plato  V.  Fig.  8),  in  whicli  the  upper  end 
of  the  organ  is  surrounded  l)y  a  large  annular  ve.s,sel  with  five  radial  and  five 
interradial  openings.  In  this  species  tho  end  of  the  outer  fold  turns  into 
a  narrow  thickened  strip,  which  ascends  spirally  toward  a  place  in  the 
fli  oiou  of  the  anal  tube.  This  structure  differs  somewhat  from  that  of 
'"etehcrinus  and  other  genera  which  have  a  thickened  edge  along  the  lower 
margin  of  the  outer  fold  passing  upward  (Plate  V.  Figs.  1,  3,  12).  In  a 
specimen  in  our  collection,  either  of  *S'/m<opW)(Hs  or  Tdelocrinus,  we  succeeded 
in  removing  at  one  side  the  two  outer  folds,  and  exim.sed  the  third  or  inner 
fold  (Plate  V.  Fig.  4),  which  has  the  form  of  a  spindle,  thicker  at  the  middle 
and  tapering  to  both  ends.  It  seems  that  the  innermost  cavity  in  all  caseo  is 
spindle-shaped,  and  that  the  inner  end  winds  spirally  upwards  like  a  screw 
with  rather  sharp,  roughened  edges,  —  the  so-called  "collar"  of  Meek  and 
Worthen.  A  connection  with  the  aiidiuhicra  has  not  been  satisfactorily 
observed  in  the  specimens ;  neither  the  upper  j)art  of  the  organ,  nor  the 
ends  of  the  and)ulacral  tubes,  have  been  found  in  perfect  pro-ervation. 

The  function  of  the  convoluted  organ  can  only  be  conjectured,  as  no 
similar  structure  has  i  oen  observed  in  recent  Crinoids ;  but  from  its  position 
it  seems  probable  that  it  was  connected  with,  or  formed  a  part  of,  the 
digestive  apparatus.  If  the  latter  was  the  case,  the  thickened  outer  end, 
leading  toward  the  anus,  may  represent  the  hind  gut. 


n 


SYSTEMATIC    PART. 


A.      Classijicittion. 

Ix  our  classification  of  1885,*  under  the  belief  that  the  Brachiato 
Crinoids  were  divisible  into  two  groups  so  widely  dift'crent  in  their  ventral 
structure  as  to  entitle  tlieni  to  rank  as  distinct  orders,  we  adopted  the  name 
Pelmatozoa  as  a  collective  term  to  include  I  be  Crinoids,  Blastoids,  and 
Cystids.  In  so  doing  we  followed  the  lead  of  Dr.  P.  II.  Carpenter,  who  t 
brought  forward  this  name  as  one  which  had  been  introduced  by  Leuckart 
in  1848 ;  with  the  differeiice,  however,  that  whereas  Carpenter  used  it  to 
designate  the  Stalked  Echinodcrins  as  a  "  branch"  of  the  "  pbyUun"  Echino- 
dermata,  and  to  include  the  Crinoidea,  IJIastoidoa,  and  Cystidea  as  classes  of 
equal  rank,  we  proposed  to  treat  the  same  collective  group  as  a  "class"  of 
the  Ecbinoderinata.  We  subdivided  the  Pelmatozoa  into  two  subclasses, 
the  first  to  contain  the  "orders"  Cystidea  and  Blastoidea,  the  second  the 
Crinoidea.     The  latter  we  divided  into  PaliDocrinoidea  and  Neocrinoidea. 

It  has  been  shown  by  Agassiz  %  that  the  name  Pelmatozoa,  although  used 
by  Leuckart  at  various  times  to  includo  the  Cystids  and  Crinoids,  —  presum- 
ably including  in  the  latter  Blastoids  also,  —  can  hardly  be  considered  as 
well  established  ;  that  it  was  not  adopted  by  any  writer  on  Crinoids  before 
Carpenter,  except  Sir  Wyville  Thomson,  and  that  Leuckart  himself,  from 
1848  to  1879,  used  Crinoidea  or  Pelmatozoa  indiscriminately  in  the  same 
sense. 

The  term  "  Pehuatozoa,"  as  having  reference  to  the  pedunculate  condi- 
tion, is  objectionable,  because  in  all  three  groups  —  Cystids,  Blastoids,  and 
Crinoids  —  there  are  many  forms  in  which  no  stem  is  found,  and  some  that 
apparently  never  had  any.     The  latter  is  probably  the  case,  among  Crinoids, 

•  Uovisinii,  Part  111.  p.  7S. 

■f  CImllpiiffcr  Report  on  the  Stalked  Crinoids,  p.  193  el  tej. 

t  Calamocriuus  Diomcdie,  p.  8. 


SYSTEMATIC   I'AUT. 


145 


i  I 


in  Marsupltes  nnd  Uliilacrinus ;  while  A(j((ssi::nrriniis,  EJrlocrlnus,  and  the 
Comiitiilu)  are  steiiilews  in  tlio  niUilt.  Among  UliwtoiJrt,  the  stt-iii  is  wiiiiting 
in  PcntaphijUum,  Triccdocrinm  and  Blcul/urovrinus  ;  and  thin  is  the  cuho  nlso 
in  a  largo  number  uf  Cyntida.  The  three  divinionsi  undouljtudly  are  nearer 
related  to  each  other  than  to  any  of  the  other  groups  of  the  Eehinoderins, 
'lot  80  much  by  reason  of  the  stem,  as  because  their  habit  of  life  is  with  the 
aouth  upward,  the  body  lying  on  its  back  or  growing  on  a  stalix,  in  contrast 
with  the  habits  of  Starfishes,  Ophiurids  and  Urchins,  which  ciiiwl  about 
mouth  downward,  and  the  Ilolothurians,  which  swim  with  the  mouth  side- 
wise.  Upon  those  characters,  perhaps,  the  Echinoderms  might  be  conveni- 
ently separated  into  three  great  groups ;  but  in  that  case  a  new  name  should 
be  adopted  in  place  of  "  Pelmatozoa." 

We  arc  now  prepared  to  accept  the  Crinoids,  Cystids,  and  Blastoids  as 
separate  groups  of  independent  rank  ;  but  what  may  be  their  exact  relative 
importance,  that  is  to  say,  what  should  be  the  exact  size  of  the  compartments 
to  be  provided  for  them  in  the  scheme  of  classification,  is  purely  a  matter  of 
opinion,  and  not  of  great  consequence.  The  tendency  of  authors  is  more 
and  more  toward  recognizing  them  as  groups  well  distinguished  from  each 
other,  and  they  are  now  ranked  generally  as  independent  classes. 

There  is  in  our  opinion  not  tho  slightest  doubt  that  the  "  Crinoidca,"  as 
proposed  by  J.  S.  Miller  in  1821,  were  limited  to  Brachiate  forms,  or,  to 
be  technically  accurate,  to  the  Stalked  Echinoderms  with  "articulate  arms." 
This  is  clearly  shown  by  his  definition,*  already  quoted  by  us  in  a  previous 
chapter.  While  including  among  his  species  both  recent  and  fossil  forms, 
Miller  did  not  refer  to  his  Crinoidea  a  single  Cystid  or  Blastoid,  although 
both  must  have  been  known  to  him.  Cystids  are  abundant  at  the  Dudley 
locality,  from  which  he  described  some  Crinoids,  and  a  Pentrcmitcs  had  been 
figured  in  1808  by  Parkinson  in  his  "  Organic  Remains,"  —  a  work  with 
which  Miller  was  no  doubt  familiar.  The  name  "  Crinoid,"  in  tho  strict  sense 
thus  employed  by  Miller,  has  been  sanctioned  by  the  usage  of  practical  natur- 
alists ever  since,  and  in  our  opinion  all  attempts  to  strip  the  term  of  its 
familiar  signification,  either  by  enlarging  or  restricting  its  meaning,  will 
prove  abortive.  If  von  Zittel,  instead  of  a  new  name  for  the  Crinoids,  had 
proposed  some  appropriate  term  for  the  larger  group,  —  to  include  the 
Crinoids,  Cystids,  and  Blastoids,  —  it  would  have  been  a  very  desirable  im- 
provement, and  we  believe  would  have  been  generally  accepted. 

•  Natural  History  of  the  Crinoidca,  p.  7. 
19 


I 


? 


MG 


TIIK   (KINOIDK.V  CAMKUATA   OF   NollTir   AMI'.UICA. 


Wliilo  ntllirring,  tlioreforo,  to  tlio  original  (lofmition  of  Millor  for  tlio 
CriiioitlH,  ami  ri'cogiii/.iiig  tlio  niiintoidH  ami  (.'ystitis  aH  tlislinct  groiijw,  of 
rclafivt'Iy  equivalent  rank,  wo  have  to  ao.  .it  tliat  tin;  tlirec  typCM  are  con- 
nected by  a  number  of  rcnuirkalde  intermediate  forinf),  and  that  it  \h  ex- 
tremely ilillicult  in  many  ciihcs  to  ascertain  wlietlier  certain  forms  arc  Crinoidn 
or  CyntidH,  or  CyHtids  or  IJhiHtoidH.  It  ImH  been  Htated  that  CrinoidH  and 
BlastoidM  are  distinguinhed  from  CyMtids  by  their  di!<tinct  penfamorouH  nyni- 
metry  ;  that  the  Blastoids  and  C\  Htids,  as  nppoHcd  to  the  Crinoidn,  have  no 
trucnrmH;  that  the  HlastoidH  have  hydroMpires,  the  Cyntids  calycine  porex, 
ifc. ;  but  the  best  of  the»o  characters  meet  with  exceptions.  Wo  find  in 
certain  Blastoids,  and  also  in  Tiamcrliius  from  the  Devonian,  and  ZiiphiHrinun 
from  the  Upper  Silurian,  only  four  radii  ;  and  even  as  late  as  the  Mesozoic 
there  are  among  the  Plicatocrinidiu  speciox  with  three,  four,  and  nIx  rays. 
P(ir<)cr!inis  Imm  tho  calyx  and  arms  of  a  Crinoid  with  calycine  pores  of  ii 
CyNtid.  IIij1)i)i'ijmIis  has  stumps  of  arms  with  recurrent  anil)uhicra  on  throo 
of  its  rays,  and  on  tho  other  two  rays  calyx  ambulacra,  which  pass  down 
the  cup  as  far  as  tho  basals.  The  genus  was  described  by  Wetherby  as  a 
Cystid,  by  Etiieridgo  and  Carpenter  as  a  transition  form  between  Crinoids 
and  mastoids ;  while  we  have  regarded  it  a  Crinoid  with  strongly  persist- 
ent Cystidean  characters.  Cdryorn'ntii*,  which  has  always  been  considered 
a  Cystid,  has  segmented  pinnule-bearing  arms  like  a  Crinoid  ;  but  it  has 
calycine  pores  and  hydrospires,  and  according  to  Carpenter  six  rays.  Codnstcr 
was  made  a  Cystid  by  E.  Billings,  by  Etheridge  and  Carpenter  a  Blastoid. 
Stij)h(tnoi'ri)iiis  was  placed  by  Roomer  among  the  Cystids,  by  Etheridge  and 
Carpenter  among  the  Blastoids,  and  wc  take  it  to  bo  a  Crinoid.  AsterohhistuH 
has  calycine  pores  like  a  Cystid,  ond  ambulacra  and  pinnules  like  a  Blastoid. 

These,  and  other  facts  that  might  be  adduced,  point  to  a  common  origin ; 
but  what  may  have  been  tho  exact  line  of  derivation  between  the  three 
groups  is  a  problem  that  is  difficult  to  solve.  They  are  found  side  by  side 
in  the  Lower  Siliuian;  but  while  tho  Cystids  ceased  to  exist  at  the  end 
of  the  Devonian,  and  the  Blastoids  at  the  close  of  the  Carboniferous,  the 
Crinoids  survived  to  the  present  day.  From  this  it  seems  to  be  evident  that 
the  Cystids,  as  the  lowest  in  rank  and  earliest  in  time,  were  the  ancestral 
type,  and  the  progenitors  of  tho  other  two ;  but  it  is  possible  that  the  Crinoids 
preceded  the  Blastoids,  although  the  latter  became  extinct  before  the  close 
of  Paloeozoic  time. 

That  the  origin  of  the  Crinoids  must  have  dated  back  far  beyond  the 


HYMKMATIC   TAUT. 


147 


Silurian  and  perliiipN  Ciinil)i'iiin  age,  U  indicated  by  tlio  lii^li  nUxto  of  dcvilnp. 
nient  wiiicli  Huntu  of  tlicir  Iuiiiih  hud  ai-(|iiii'i-d  hh  vnv\y  an  tliu  Ticntun 
Hi'oup,  wliL'n  they  liad  in  Moino  ciinfrf  ahnost  coiiiplctuly  thrown  ulV  their 
CyHtid  ciiamcterH.  A  Htriiiing  exaniplu  of  tliiH  nniung  the  Canierata  Ih  (teen 
in  the  genns  (thjiitorrintw,  in  wliicli  wo  find  associated  with  certain  primitive 
charactern  a  hi^h  degree  of  perlection.  It  m  less  perceptiiile  among  the 
Inadimata,  in  which,  notalily  in  tho  llyhocrinida',  OyHtidean  fcaturoN  arc 
strongly  intermingled  with  the  characters  of  the  larval  Crinoi<l.  IJiit  even 
ninong  them  it  is  imposxihle  with  the  knowlcdgt'  wo  have,  or  are  likely  to 
obtain,  to  form  a  conjecture  as  to  the  group  of  Cyst  ids  from  Mhich  they  are 
originated,  and  this  is  readily  explained  if  we  consider  that  the  two  typos 
followed  independent  lines  of  development,  and  departed  from  one  another 
more  and  more  in  geological  time. 

The  general  tendency  of  the  Crinoid  t;  pe,  taken  as  n  whole,  has  been 
towanl  jjcntamerous  symiMctry,  and  in  tliis  ti.ey  ditTor  oswentially  from  most 
of  the  Cystids.  But  the  jientamerons  tendency  had  to  struggle  with  other 
tendencies,  which  in  various  ways  from  time  to  time  carried  one  or  the  other 
of  the  subordinate  groups  far  off  in  otler  directions.  A  disturbance  of  this 
kind  was  caused  by  the  introduction  ^f  anal  p'  os,  by  means  of  which  the 
l)entamcrous  symmetry  wa«  temporarily  distu;  1  by  a  bilateral  one,  which 
for  a  time  threatened  to  overshadow  the  for,,icr,  imtil  finally  after  the  elimi- 
nation of  those  plates  the  pcntame  >  :v  ynimetry  was  iinanently  leotored. 
The  phases  through  which  the  a'  .il  p^  les  pa.ss  in  geological  time  in  the 
various  groups  arc  well  represented  by  individual  growth  in  fi  '  !  rva  of 
Anifddii,  and  have  proved  to  be  excellent  characters  for  family  and  generic 
divisions. 

The  earliest  fossil  Crlnoids  have  no  special  anal  plate,  and  were  more  or 
loss  strictly  pentamerous.  Among  the  Lower  Silurian  Camerata  the  nnal 
X  is  represented  only  in  the  Reteocrinido)  and  in  the  abberrant  genus  Co)iij)- 
socrhiits ;  in  all  others  the  plate  is  wanting.  It  is  absent  also  in  the  genus 
Ichthi/ocrinus,  one  of  the  earliest  forms  of  the  Articulata,  and,  as  we  think, 
the  precnrsor  of  a  large  series  of  genera  with  anal  plates.  It  piol)ably 
was  represented  ear''  '•  in  the  Fistulata  than  in  the  other  groups,  as  might 
be  expected,  for  ai: w  them  all  tendencies  toward  further  development 
seem  to  have  been  exhibited  upon  the  posterior  side. 

But  there  were  other  influences,  not  due  to  the  anal  plates,  and  not  di- 
rectly traceabbr!  to  anything  shown  by  embryology,  which  not  only  disturbed 


148 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


the  radial  symmetry,  but  the  bilateral  as  well,  and  strongly  siiggest  that 
the  Crinoids  hud  to  wrestle  for  a  long  time  with  the  tendencies  derived  from 
their  Cystid  antecedents,  manifesting  themselves  in  a  variety  of  irregular- 
ities, which  from  time  to  time  characterized  special  groups.  Such  are  the 
presence  of  compound  radials  in  one  or  more  rays;  the  variations  in  the 
form  and  composition  of  the  proximal  ring  in  the  base ;  the  non-arm  bearing 
radials  of  Bacrocrbius,  Atdextucriims,  and  IVibracldocrinus ;  the  irregular 
number  of  radials  —  more  or  less  than  five  —  of  the  Plicatocrinidoc  ;  and 
the  almost  complete  obliteration  of  symmetry  among  the  Pisocrinida)  and 
Calccocrinidao. 

The  division  of  the  Crinoids  into  two  orders:  " Palococrinoidea "  and 
"  Stomatocrinoidea  "  WiXs  proposed  by  us  on  account  of  the  apparent  differ- 
ence in  the  conditions  of  the  actinal  portions  of  the  calyx,  whereby  mouth 
and  food  grooves,  and  the  ventral  disk  generally,  of  all  Pal.Tozoic  Crinoids, 
without  exception  as  we  supposed,  was  covered  by  a  special  integument  — 
the  "vault"  of  antecedent  literature  —  instead  of  being  external  and  exposed 
to  view.  With  the  knowledge  we  then  had  this  seemed  to  be  a  character 
morphologically  of  extreme  importance,  and  it  was  so  regarded  by  others. 
Under  the  order  Palivocrinoidea  we  placed  all  Crinoids  with  covered  mouth 
and  closed  food  grooves,  and  under  the  Stomatocrinoidea  those  in  which 
mouth  and  food  grooves  are  exposed.  The  two  groups  were  accepted  by 
Carpenter,  but  he  changed  the  name  of  the  latter  into  "  Neocrinoidea." 

Anotlier  classification  was  introduced  by  Ncumayr,*  who  proposed  the 
name  "  Ilypascocrinoidea "  for  all  Crinoids  in  which  mouth,  ambulacra! 
vessels,  and  SaumpUittchen  (the  latter  if  present)  are  beneath  the  tegmen ; 
and  the  "  Epascocrinoidea  "  for  those  forms  in  which  the  ambulacra  are  not 
covered  by  the  tegmen,  but  have  external  grooves,  which  are  either  exposed 
or  closed  by  movable  SaumpUittehen.  Under  the  latter  he  arranged  all  recent 
Crinoids  with  our  Fistulata;  under  the  former  the  Ichthyocrinidae  and  Haplo- 
crinidne  together  with  our  Camerata.  It  is  surprising  that  Neumayr's  classi- 
fication, while  based  like  ours  upon  the  condition  of  the  mouth  and  surround- 
ing parts,  led  to  such  different  results.  This  must  be  attributed  largely  to 
the  interpretation  which  he  gave  to  the  disk  of  Cijatliocrinus,  in  which  he 
took  the  vacant  space  found  in  the  centre  of  imperfect  specimens  for  the 
mouth,  and  to  the  fact  that  he  was  unacquainted  with  the  ventral  structure 
of  the  Ichthyocrinidas. 

•  Die  Stammc  dcs  Thierreicbes,  18S0,  p.  462. 


a. 


SYSTEMATIC  PART. 


149 


When  we  discovered  that  the  ventral  surface  of  Taxocrinus,  and  probably 
of  all  IchthyocrinidaB,  is  covered  by  a  disk  almost  like  that  of  recent  Crinoitls, 
and  that  it  possesses  an  open  mouth  and  open  food  grooves,  it  was  instantly 
apparent  to  iis  that  a  division  upon  the  line  of  Palaeozoic  and  Neozoic 
Crinoids  could  no  longer  be  maintained.  Tiie  moment  this  truth  was 
recognized,  it  was  found  to  be  reinforced  by  other  considerations  wliich  were 
fully  set  forth  by  us  at  the  time.*  It  might  have  seemed  practicable  to 
retain  the  two  grand  divisions  upon  the  same  characters  as  before,  by  trans- 
ferring the  Ichthyocrinida)  to  the  division  containing  the  recent  Crinoids ; 
but  this  would  have  made  a  change  of  the  names  unavoidable.  Besides,  the 
fact  chat  those  characters  go  back  as  far  as  the  lowest  Sihu'ian  was  enough 
to  suggest  the  gravest  doubts  whether  the  particular  condition  of  the  ventral 
covering  was  morphologically  as  important  as  we  had  supposed. 

About  the  same  time  we  came  into  possession  of  specimens  of  the 
Camerate  genus  Platycrimis  with  orals  almost  perfectly  sj-mmetric,  and  the 
covering  plates  of  the  ambulacra  most  regidarly  arranged.  Considering  that 
in  this  same  genus  there  are  species  in  which  the  tcgmen  is  composed  of  as 
heavy  plates  as  in  any  Actinocrinus  with  subtogininal  ambulacra,  the  con- 
clusion forced  itself  upon  us  that  the  plates  of  the  tegmen  in  all  these  forms 
represent  the  same  element,  and  that  the  most  rigid  "vaidt"  of  Palaiozoic 
Crinoids  is  but  a  modifled  disk. 

The  change  in  our  views  was  announced  in  our  paper  on  "  The  Perisomic 
Plates,"  t  in  which  we  gave  up  the  Palaiocrinoidea  and  Neocrinoidea  as 
natural  groups,  and  proposed  in  place  of  them  the  Camerata,  Inaduiiata,  and 
Art'miluta. 

A  separation  of  the  older  Crinoids  into  three  divisions  was  attempted  by 
us  as  early  as  1877,  and  all  that  we  have  since  learned,  whether  through  our 
own  observations  or  those  of  other.s,  has  tended  to  confirm  their  viilidity. 
Now  that  we  have  got  rid  of  the  imaginary  line  between  Palosozoic  and 
later  Crinoids,  we  can  better  realize  the  importance  of  these  group.s,  espe- 
cially since  we  find  that  they  can  be  applied  to  all  Crinoids,  recent  as  well 
as  fossil. 

We  regard  as  the  most  important  characters  for  dividing  the  Crinoids 
into  orders :  — 

1st,  the  condition  of  the  arniB  —  whether  free  above  the  radials,  or  partly  incorporated 
into  the  calyx. 


n 


Proc.  Acad.  Nat.  Sci.  Phila.,  1SS8,  p.  350,  et  itq. 


t  Ibid.,  p.  343. 


150  THE  CRINOIUEA  CAMERATA  OF  NORTH  AMERICA. 

2d,   tlio   mode  of  uiiiou  between  tlie    plates  of  tlie   calyx  —  whether  movable  or 

iiiimovable. 
3d,  the  eoiiditioii  of  the  stem  —  whether  the  young  joints  were  formed  beneath  tlio 

proximal  ring  of  the  calyx,  or  beneath  the  top  stem  joint. 

The  inorpliologiciil  importance  of  these  characters  is  shown  by  the  fact  that 
among  the  earlier  Crinoiils  tiiey  appear  as  well  defined  as  among  tlio.se  of 
later  epochs,  which  indicates  that  the  origin  of  the  three  gronps  dates  back 
to  a  much  earlier  time. 

The  Crinoidea  I\.\dunata  represent  the  simplest  form,  their  dorsal  cup 
being  composed  invariably  of  only  two  rings  of  plates,  or  three  when  infra- 
basals  arc  present.  It  has  no  supplementary  plates,  except  nn  annl  piece, 
but  this  is  not  represented  in  all  of  them.  The  radials  at  four  sides  of  the 
cup  are  in  lateral  contact,  and  the  arms  are  free  from  the  radials  up. 

In  the  structure  of  the  ventral  disk  we  recognize  two  different  plans; 
the  one  exhibiting  the  utmost  simplicity,  being  com])Osed  exclusively  of  five 
large  oral  plates  forming  a  pyramid  ;  the  other  showing  considerable  com- 
plexity at  the  posterior  interradius,  which  is  drawn  out  into  a  sac  or  tube. 
Upon  these  two  plans  we  divide  the  Tnadunata  into  two  subgroups:  The 
Inadixata  Lai!VIFOr.mia,  and  the  Ixaduxata  Fjstulata,  both  embracing 
monocyclic  and  dicyclic  forms. 

The  calyx  of  the  Larvifonnia  consists  of  but  few  plates ;  viz. :  basals 
—  occasionally  infrabasals  —  radials  and  orals,  the  latter  forming  a  closed 
pyramid  wliich  rests  against  the  radials ;  the  mouth  is  closed,  and  the  am- 
bulacra are  not  exposed  to  view.  The  arms  are  simple,  non-pinnulate,  one 
to  each  ray,  and  they  are  composed  of  long,  quadrangular  joints  which, 
except  upon  the  radials.  arc  united  by  close  suture.  The  anus  is  excentric. 
either  piercing  the  posterior  oral,  or  situated  between  the  orals  and  radials, 
and  is  sometimes  extended  out  to  the  end  of  a  long,  narrow  tube.  One  can 
scarcely  imagine  a  more  complete  parallelism  than  there  is  between  these 
ancient  Crinoids  and  the  larval  state  of  recent  ones,  and  it  was  this  that 
suggested  the  name  of  the  group,  which,  as  we  believe,  represents  the  most 
primitive  type  of  the  Crinoids  generally.  That  we  do  not  find  the  Larvi- 
formia  prior  to  the  Ningnra.  but  only  subsequent  to  the  advent  of  the  other 
groups,  may  be  accounted  for  by  the  pmall  size  of  their  species.  The  calyx 
of  AUfujerrimis  Ausiinii  from  the  Scotch  Carboniferous  is  no  larger  than 
a  small  grain  of  sand,  and  it  is  vorv  possible  that  the  earliest  forms  were 
altogether  microscopic.     The  total  absence  of  supplementary  plates,  and  the 


n-^ 


i 


'  ^ 


SYSTEMATIC  PART. 


lol 


compound  nature  of  the  radials  in  the  eiiriier  forms,  are  other  primitive 
features  characteristic  of  this  group. 

The  Fistulata,  in  a  general  way,  agree  in  the  structure  of  the  dorsal  cup 
with  the  Larviformia.  But  while  in  the  latter  the  disk  is  simple  in  the 
extreme,  that  of  the  Fistulata  is  highly  specialized  by  means  of  the  extrava- 
gant development  of  the  posterior  interradius,  forming  a  tube  or  sac  which 
often  is  drawn  out  to  the  full  )'>ngth  of  the  arms.  The  sac  rests  upon  the 
radials  or  is  supported  by  the  anal  x,  and  frequently  —  not  always  —  con- 
tains the  anus.  Owing  to  the  large  size  of  this  sac,  and  the  disturbances 
thereby  produced,  the  whole  calyx  acquired  a  marked  irregularity,  which 
was  still  further  increased  in  species  with  compound  radials,  so  that  the 
pentamerous  symmetry,  and  the  bilateral  also,  were  often  supplanted  by 
asymmetry.  The  other  interambulacral  areas  are  but  feebly  developed,  and 
are  pushed  over  toward  the  anterior  side.  The  anal  opening  is  situated 
near  the  top  of  the  sac,  or  at  some  place  along  its  anterior  side,  and  some- 
times in  front  of  the  sac  close  to  the  mouth.  The  sac,  at  least  in  some 
groups,  is  pierced  by  pores,  which  we  think  had  respiratory  functions, 
similar  to  the  water  pores  of  recent  Crinoids,  in  which  also  they  are  more 
profusely  distributed  at  the  posterior  area  than  at  any  of  the  four  other  sides. 
In  some  groups,  in  which  the  sac  is  not  perforated,  we  discovered  upon  the 
disk,  directly  behind  the  mouth,  a  poriferous  plate,  a  sort  of  madreporite, 
which  probably  performed  the  same  functions  as  the  pores  in  the  others. 

The  CiMNoiDEA  Camerata  have  a  largo  number  of  supplementary  pieces, 
which  are  distributed  almost  equally  throughout  the  five  sides  of  the  calyx, 
by  means  of  which  the  proximal  arm  plates  for  some  distance  are  incor- 
porated into  the  calyx,  thereby  increasing  the  capacity  of  the  visceral  cavity. 
All  plates  of  the  calyx  are  heavy  and  immovable,  being  united  by  close 
suture.  The  symmetry  of  the  dorsal  cup  is  either  strictly  pentamerous  or 
sub-bilateral ;  we  never  find  that  asymmetry  which  is  so  characteristic  of 
some  of  the  Fistulata.  The  base  is  monocyclic  or  dicyclic,  and  mouth  and 
food  grooves  are  perfectly  closed. 

The  CiuxoiDEA  AuTicuLATA  agree  with  the  Camerata  in  that  their  lower 
l)rachials  take  part  in  the  calyx,  and  help  to  enclose  the  visceral  mass ;  but 
their  plates  from  the  radials  up  are  movable.  The  incorporation  of  the 
brachials  took  place  by  lateral  union  among  themselves,  by  the  introduction 
of  supplementary  plates,  or  by  means  of  an  incrusted  or  naked  skin ;  and 
mouth  and  food  grooves  are  exposed  upon  the  disk.     The  base  is  dicyclic. 


? 


152 


THE  CRIXOIDEA  CAMKRATA  OF  NORTH  AMERICA. 


I'  ^ 


but  the  infrabasals  arc  fused  with  the  top  stem  joint,  which  throughout  this 
order  is  not  the  youngest  joint  of  the  stem. 

To  the  Articulata  we  refer  the  Ichthyocrinidaj,  and  all  Meso/oic  and  later 
Crinoids  —  recent  and  fossil  —  in  which  the  new  stem  joints  are  introduced 
beneath  the  top  joint.     They  are  divisible  into  two  suborders  :  — 

I.  The  Articulata  Impinnata,  to  include  the  Ichthyocrinidaj  which  are 
destitute  of  pinnules. 

II.  The  AitTicuLATA  PiXNATA,  to  include  those  families  in  which  pin- 
nules are  present. 

Tliat  there  exists  a  close  resemblance  between  the  Ichthyocrinidic  and  Coma- 
tula) —  especially  their  earlier  .stages  —  is  well  shown  by  our  illustrations 
on  Plate  VI.  Figs.  13  to  20,  and  it  is  worth  mentioning  that  no  other  form 
has  changed  so  little  in  geological  time  as  the  genus  Ichlhijocrinus,  which 
survived  from  the  Lower  Silurian  to  the  Coal  Measures,  and  which  may  be 
regarded  as  the  ancestor  of  all  Articulata. 

The  name  "  Articulata "  was  proposed  by  J.  S.  Miller,  and  adopted  by 
Johannes  Midler  for  a  subdivision  of  the  Crinoidea.  The  former  referred  to 
it  Ajjiocriniifi,  Encnmis,  and  Pentacrlnns,  to  which  Miiller  added  the  Coma- 
tulao.  He  defined  the  group  as  one  in  which  the  lower  ray  plates  are  con- 
nected laterally  by  a  skin,  which  may  be  naked,  or  paved  with  irregular 
plates.  From  this  definition  we  judge  that  his  ideas  of  the  group  were 
substantially  the  same  as  ours,  and  we  believe  if  Miiller  had  known  the 
Ichthyocrinidtv,  he  would  have  placed  them  together  with  the  Apio- 
crinidiv  and  Comatula?.  His  definition,  however,  is  not  complete  enough, 
and  it  admits  forms  which  in  our  opinion  are  widely  different.  We  al- 
lude to  the  Encrinidtv)  and  Pentacrinidic,  which  differ  from  the  Apio- 
criniihe  and  Conuitulae  in  having  the  uppermost  joint  of  the  stem  the 
youngest  joint,  whereas  in  the  latter  two  it  is  not.  That  Miiller  admits 
Paitacriniis  into  this  group  we  can  understand  —  its  lower  brachials  actually 
are  united  by  a  skin  —  but  it  is  difiicult  to  .see  why  lie  added  the  genus 
Eiwriims,  in  which  the  rays  are  free  from  the  radials  up.  The  Pentacrinidiv 
have  through  the  Encrinido)  close  affinities  with  the  PotcriocrinidoD,  and  are 
probably  their  descendants;  but  if  they  are  Inadunata,  thoy  represent  an 
aberrant  type,  for  their  lower  brachials,  as  stated  before,  arc  enclosed  in  the 
calyx.  This  departure  from  the  Inadunate  plan  may  perhaps  be  explained 
if  we  consider  'hat  the  calyx  of  the  Pentacrinidao,  owing  to  the  reduction  of 


SYSTEMATIC  PART. 


153 


the  ventral  pac,  was  incapable  of  hokling  the  visceral  mass  without  incorpor- 
ating the  lower  brachials.  As  such  the  Pentacrinidio  may  represent  the  last 
survivors  of  an  exhausted  type,  or  they  are  the  progenitors  of  a  new  group. 

After  eliminating  from  the  Articulata  the  Encrinidte  and  Pentacrinidoc, 
and  all  Crinoids  in  which  the  top  stem  joint  is  the  youngest  joint  of  the  stem, 
we  have  a  well-defined  group  ;  but  it  may  be  asked  whether  tlie  name 
Articulata  c;in  be  retained  for  a  group  thus  restricted  and  redefined.  The 
name  is  most  appropriate,  and  as  the  group  is  based  largely  on  the  character 
of  Mliller,  we  think  it  is  just  to  the  author  to  adopt  his  name.  In  case,  how- 
ever, other  writers  conclude  that  this  course  is  inadmissible,  we  propose  llie 
name  "  Articulosa"  to  take  the  place  of  Articulata,  to  meet  the  coutiugenry. 

That  our  primary  divisions  are  natural  groups  is  further  confirmed  by  tlie 
orientation  of  the  base,  which,  when  the  proximal  ring  of  the  base  is  un- 
equally tripartite,  varies  among  the  different  groups.  Comjiaring  the 
base  to  tlie  dial  of  a  clock  witirthc  anal  side  at  12,  it  may  be  said  tiiat  in 
the  Impiimata  the  .smaller  infrabasal  points  to  2  o'clock;  in  the  dicyclic 
Fistulata,*  so  far  as  observed,  and  in  the  Antcdon  larva,  according  to  Bury, 
to  6  o'clock ;  and  that  the  small  basal  in  monocyclic  Crinoids  generally 
points  to  7  o'clock,  contiary  to  all  Blastoids,  in  which  it  points  to  5  o'clock. 
We  have  no  explanation  of  these  facts  to  offer,  but  tlicy  doubtless  have  an 
important  bearing  upon  the  derivation  of  the  groups. 

It  is  now  well  establi-^lied  that  the  value  of  a  character  for  classificatory 
purposes  is  not  always  in  proportion  to  its  physiological  importance  ;  but 
depends  more  on  its  constancy  throughout  groups,  and  its  correlation  with 
other  characters.  I'he  characters  of  any  group  are  not  fixed  and  rigid,  but 
w  must  always  be  prepared  to  find  as  to  one  or  more  of  them  variations  or 
departures  from  the  typical  form,  indicating  a  transition  toward,  or  con- 
nection with,  some  other  group  through  that  particular  feature.  We  cannot 
expect  absolute  persistence  of  any  one  character,  whether  specific,  generic, 
or  ordinal,  and  the  larger  our  collections  the  less  persistent  and  fixed  will  we 
find  the  separate  characters.  But  if  we  are  reasonably  happy  in  our  identi- 
fications, we  may  expect  to  find  greater  reliance  to  be  put  upon  llie  corre- 
lation of  characters,  .so  that  while  one  or  more  of  them  will  show  a  tendency 
to  departure,  the  sum  of  all  will  exhibit  a  predominance  which  will  liold  the 
form  in  question  within  the  given  group.  There  is  no  hard  and  fast  rule  by 
which  it  may  be  determined  that  a  certain  character  is  of  "  family "  or 
"  generic "  importance.     It  may  bo  the  one  or  the  other  according  to  cir- 

•  This  dues  not  liolil  good  for  the  Fistiilritn  since  Mr.  Unllior — Criiioiilrn  of  Gotlniid,  Vol.  I.  p.  152^ 
Ims  found  tlint  the  poaitiou  of  tbo  small  infrabasal  is  not  coustint  iu  the  Gjtland  species  of  Giuocrinua, 

20 


? 


154 


THE  CRIXOIDEA  CAMEiiATA  OF  NORTH  AMERICA. 


ciimstancos,  iind  about  all  we  can  say  of  tlie  "  value "  of  any  character  ia 
that  its  value  is  proportional  to  the  extent  to  which  it  tends  to  combine 
subordinate  groups.  As  n  rule  we  may  say  that  a  character  which  j)asses 
down  to  earlier  geological  epochs,  is  of  greater  value  in  classification  than 
one  dating  from  u  later  period. 

It  hah  been  stated  that  the  supplementary  plates  afford  excellent  charac- 
ters for  dividing  the  Crinoids  into  primary  divisions ;  but  they  are  also  of 
great  importance  in  the  separation  of  families.  It  may  appear  singular  that 
plates  whoso  chief  function  it  is  to  fill  up  spaces  between  other  plates,  and 
which  are  of  but  secondary  importance  morphologically,  should  have  so 
great  a  value  in  classification;  but  such  is  undoubtedly  the  case.  The  elimi- 
nation of  those  plates  from  the  calyx  would  reduce  all  Crinoids  to  a  single 
group,  and  tlicse  would  all  be  Larvilormia.  The  introduction  of  sup|)lo- 
mentavy  plates  into  the  simplest  Inadunate  type  produces  the  Fistulata, 
Camerata,  and  Articulata,  and  all  in  their  individual  development  necessarily 
passed  through  the  Larviformia  stage. 

Among  the  supplementary  plates,  the  anals  unfjucstionably  take  the  first 
rank.  Tiie  absence  of  anal  plates,  their  introduction  into  the  calyx,  and  the 
relations  they  bear  to  adjoining  plates  —  whether  introduced  between  the 
radials  or  l)rachials,  or  between  both  of  them  —  has  been  regarded  as  very 
important  ;  but  the  same  characters  have  not  the  same  classificatory  value 
in  every  group.  The  differentiations  produced  by  the  anal  plates  have  been 
considered  of  fiimily  importance  among  the  Camerata,  but  among  the  Fistu- 
lata  and  Tmpinnata  appear  to  be  of  generic  value  only. 

The  nature  of  the  base,  whether  composed  of  one  ring  of  plates  or  two,  is 
a  valuable  character  for  distinguishing  famili'^s,  but  we  tiiougiit  it  expedient 
to  make  an  exception  to  this  rule  in  the  case  of  the  Reteocrinida*,  under 
which  we  have  united  monocyclic  and  dicyclic  forms.  The  number  of  basals 
and  infrabasals  is  of  generic  value  only. 

The  occurrence  of  inferradials  among  Inadunata  and  Articulata,  and  the 
modifications  they  undergo  paltrontologicall)',  and  their  final  disajipearance. 
have  furnished  good  generic  characters. 

Somewhat  less  intportant  from  a  classificatory'  standpoint  is  the  number 
of  costals,  although  it  was  made  a  generic  character  among  the  Camerata; 
while  in  the  Fistulata  it  has  in  some  cases  no  significance  at  all. 

The  general  structure  of  the  disk  affords  good  characters  for  dividing  the 
Crinoids  into  ordinal  and  subordinal  groups.     It  was  the  total  absence  of 


">  i 


,    f- 


SYSTf:>IATlC  PART. 


155 


perisomlc  plates  in  the  disk  that  suggested  the  Larvifoniiia,  and  the  sac- 
hlie  prolongation  of  its  posterior  area  tlie  Fistuhvta ;  all  Cauiorata  have 
a  rigid  disk,  contrasting  therein  with  the  Articulata  in  which  the  disk  is 
pliable. 

Tlie  condition  of  the  ambulacra,  whether  resting  \ipon  the  tegnicn  or 
being  incorporated  into  it  by  means  of  their  covering  pieces,  or  whether 
constituting  open  furrows  upon  the  disk,  is  of  more  than  family  importiineo ; 
but  the  exposure  of  the  covering  pieces,  and  their  concealment  wholly  or  in 
part  by  the  encroaching  perisonie,  are  not  even  reliable  generic  characters. 

The  presence  or  absence  of  orals,  and  their  greater  or  loss  symmetry  or 
asymmetry,  have  very  little  classificatory  value,  except  in  the  Larviforniia, 
in  which  they  are  the  only  plates  of  the  disk. 

The  condition  of  the  anus,  whether  in  form  of  a  simple  opening  directly 
piercing  the  calyx,  or  situated  at  the  end  of  a  tube,  has  been  generally 
regarded  as  of  generic  value. 

Of  considerable  importance  is  the  presence  or  absence  of  pinnules,  which 
is  correlated  with  other  characters  by  which  very  large  families  are  dis- 
tinguished, c./^.,  the  Cyathocrinida)  from  the  Poteriocrinidae ;  and  it  is  the 
name-giving  character  of  the  Pinnata  and  Impinnata. 

The  condition  of  the  arms,  their  simplicity,  their  mode  of  branching,  and 
the  arrangement  of  their  plates  —  whether  uniserial  or  biserial  —  afford 
useful  characters  for  distinguishing  genera;  but  as  all  biserial  arms  are 
derived  phylogenetically,  as  they  are  embryologically,  from  the  uniserial 
ones,  it  must  be  expected  that  at  a  certain  time  both  structures  occur  side 
by  side  in  the  same  genus. 

The  construction  of  the  stem,  the  form  of  the  joints,  the  length  of  the 
internodes,  have  comparatively  little  value  in  the  classification  of  Palaeozoic 
Crinoids,  and  are  of  generic  value  only  in  rare  cases.  Perhaps  if  the  stems 
were  oflener  and  more  completely  preserved,  it  would  help  in  the  identifica- 
tion of  species. 

With  regard  to  species,  their  recognition  is  to  a  considerable  extent  the 
expression  of  the  individual  opinion  of  the  observer,  and  in  large  collections 
it  is  often  difiTicult  to  distinguish  between  species  and  variety.  So  long  as  we 
have  to  deal  with  new  forms,  represented  by  unique  specimens,  the  task  is 
simple  enough.  But  when  large  numbers  of  specimens  are  brought  together, 
in  dilferent  states  of  preservation,  presenting  different  conditions  of  growth 
and  size,  and  exhibiting  the  various  shades  of  individual  variation,  it  is  not  so 


? 


* 


t     ;l 


H 


156 


THE  CRIXOIDEA  CAMKRATA  OF  NORTH  AMCTICA. 


easy  to  discover  and  di-fiuo  the  points  by  wliich  ccrtiiin  nsseinblnges  of  these 
iiidivitluiilM  agree  with  each  other,  niul  diller  from  others,  witii  siidicient  con- 
stancy to  be  called  species.  With  but  a  single  specimen  in  hand,  and  this 
imperfectly  preserved,  as  is  oftin  the  case,  it  is  impossible  to  decide  whether 
we  have  a  good  species  or  a  mere  variation,  whether  it  is  tlio  young  or  the 
adult;  and  whether  or  not  the  distinguishing  character  represents  a  mere 
abnormal  condition  of  some  established  species.  In  describing  new  species, 
therefore,  the  utmost  caution  is  re(iuired,  especially  since  the  number  of 
described  species  in  America  alone  has  increased  to  almost  fifteen  hundred. 
That  a  specimen  comes  from  virgin  soil,  distant  from  any  other  known 
locality  of  the  same  horizon,  does  not  make  it  a  dillerent  species.  The 
geographical  range  of  species  is  much  wider  than  formerly  supposed,  and 
careful  comparison  with  authentic  specimens  of  allied  forms  must  always  be 
made  before  a  form  can  be  recognized  as  a  valid  species.  Among  tlie  char- 
acters to  be  considered  as  most  important  for  distinguishing  species,  we 
recognize  the  form  and  proportions  of  the  calyx;  the  relative  proportions  of 
the  plates  and  their  ornamentation ;  the  number  of  arms  and  arm  openings, 
the  direction  of  the  latter,  and  their  distribution  around  the  caly.x,  whether 
continuous  or  separated  by  the  supplementary  plates;  the  form  and  position 
of  the  orals,  whether  flat  or  tumid,  symmetrically  or  asymmetrically  arranged ; 
the  presence  of  "radial  dome  plates"  or  regular  covering  pieces,  and  other 
characters  of  a  more  specialized  nature ;  not  forgetting  that  some  of  them 
depend  on  the  more  or  less  adult  condition  of  the  specimen,  and  its  preserva- 
tion, and  that  in  certain  groups  some  of  them  are  wholly  worthless. 

That  a  given  character  mav  bo  good  in  one  group,  and  without  any 
value  for  classification  in  another,  is  a  fact  so  fully  recognized  at  the  present 
day  that  there  is  no  need  of  citing  instances  to  prove  it.  Every  working 
naturalist  has  encountered  striking  illustrations  of  its  truth. 

To  facilitate  the  identification  of  species  among  genera  containing 
a  largo  number  of  forms,  we  have  arranged  our  descriptions  so  as  to  place 
species  which  are  most  clo.sely  related  next  to  each  other,  thereby  en- 
abling the  student  to  make  satisfactory  comparison  with  allied  forms.  In 
Plafi/crhuts,  which  contains  an  unusually  large  number,  we  have  arranged 
the  species  into  subordinate  groups. 

It  is  not  our  intention  to  go  into  details  upon  the  classification  of  the 
Inadunata,  but  a  ."^hort  review  of  them  will  be  necessary  for  this  work. 

We  have  stated   that  we  divide   the  Inadunata  into  Larviformia  and 


SYSTEMATIC  PART. 


157 


Fistulata.  The  former  embrace  tlie  fftmilies  IlnplocrinidoD,  Piaocr'mi(]a\ 
SymbathocrinidoD,  niul  CuprosHocrinidao;  the  latter  the  Ilybocrinida^,  Iletero- 
crinuluD,  Anomalocrinida),  Belcmnocrinidao,  Gasterocomido),  Catillocrinidip, 
nnd  Calceocrinida)  of  monocyclic  forms,  and  the  Dcndrocrinldao,  Cyathocri- 
nidoD,  Potoriocrinida),  Astylocrlnidro,  Eiicrinidas,  and  Pentacrinidaj  among 
dicyclic  forms.  The  arranj^cment  is  substantially  the  same  as  that  proposed 
by  us  in  1885,  in  Part  III.  of  the  Revision,  except  that  we  withdraw  the 
GasterocomidoD  from  the  Larviformia,  and  jilace  them  among  the  Fistulata. 
This  change  was  announced  by  us  in  1890,*  when  we  restricted  the  Larvi- 
formia to  those  Inadunatu  in  which  the  orals  rest  against  the  radiala,  nnd  the 
ventral  surface  is  covered  exclusively  by  the  <  i  ils,  i.  e.,  Crinoids  which 
remain  persistently  in  the  larval  state. 

A  dilTerent  division  of  the  Inadunata  has  been  lately  proposed  by  Mr. 
Bather,t  who  subdivided  the  Inadunata  into  "  Monocyclica  "  and  "  Dicyc- 
lica ; "  but  whether  they  should  be  ranked  as  suborders,  he  leaves  as  yet  in 
doubt.  In  alluding  to  tiie  Larviformia  and  Fistulata,  Bather  says  these  divi- 
sions "  cannot  well  be  maintained.  Many  genera  hitherto  included  in  the 
Larviformia  have  quite  as  good  a  ventral  sac  as  some  acknowledged  Fistu- 
lata." We  do  not  know  of  any  group  to  which  this  remark  can  be  applied, 
unless  Mr.  Bather  undertakes  to  homologize  the  narrow  anal  tube  oi S;imb(itho- 
crimts  and  Pisocrlnns  with  the  ventral  sac  of  the  Fistulata.  Sj/mhat/i(irrhuis 
has  no  ventral  sac,  but  simply  an  anal  tube,  nor  has  it  an  anal  jilato,  or 
perisomic  pieces  as  we  once  supposed ;  its  asj-mmetrical  oral  pyramid  rests 
directly  upon  the  radials,  and  its  anal  tube  is  supported  by  the  radials  and 
orals  together.  Bather  further  says :  "  they  (W.  and  Sp.)  excluded  Ilctcro- 
criiiKs  and  Calceocriniis,  in  which  it  has  at  all  events  never  been  proved 
that  other  plates  beside  orals  occur  in  the  tegmen."  We  supposed  it  was 
now  admitted  that  the  ventral  sac  represents  morphologically  the  highly 
developed  posterior  inter-palmar  area  of  the  disk,  as  was  proved  by  the 
position  of  the  anus,  which  is  situated  either  at  the  imlerbr  side  of  the  sac, 
or  not  within  the  sac  at  all,  but  in  front  of  it  (toward  the  oral  centre)  in  ihe 
main  part  of  the  tegmen.  Admitting  this,  the  presence  of  the  sac  proves 
that  the  Ileterocriuidao  had  a  complicated  di.sk. 

The  case  is  very  similar  in  the  Calceocrinida)  and  Catillocrinida3.  IjoIIi 
agree  with  the  Larviformia  in  having  no  anal  plate,  at  least  no  anal  x;  but 

»  IVocfcd.  Acad.  Xat.  Sci.  Pliila.,  1S91,  p.  335. 

t  'i'liu  Criuuidca  of  Uutlaud,  I'urt  I.,  willi  tcu  plates  (Stockholm,  1893),  p.  20. 


? 


i 


hi 


I  ; 


^i 


158 


THE  ClUNOIDEA  CAMEKATA  OF  NOUTII  A.MEUICA. 


there  are  roHting  upon  tlic  rndiu1»  what  wu  tiiko  to  be  plates  uf  tliu  tube. 
ThcMC  i)latoH,  which  are  crcsccut-Hliapcd  and  extroiiifl^'  heavy,  are  longitu- 
dinally arranged,  and  puna  np  to  near  the  top  of  the  arniH.  The  relation  of 
these  plates  is  not  altogether  clear,  but  they  probably  represent  the  heavy 
and  solid  plates  ot  lucriiiun,  which  constitute  the  ridge  along  the  posterior 
side  of  the  sac ;  and  we  believe  that  the  oi)i>n  groove  at  the  anterior  side  was 
in  the  animal  filled,  as  in  the  case  of  lucrimis,  by  small  disk  plates,  which 
may  or  may  not  have  been  perforated.  This  interpretation  seems  to  us 
the  most  probable,  and  u[ion  the  strength  of  it  we  have  placed  both  families 
under  the  Fistulata. 

Bather's  definition  of  the  Monocyclica  is  short:  "Inadunata  with  no 
infrabasals."  But  notwithstanding  its  brevity  it  meets  with  two  exceptions: 
Cttpressocrinus  and  Mi/rtiloc.rinua,  which  Bather  referred  to  the  Monocyclica 
with  some  doubt;  both  have  an  infrabasul  disk.  It  will  not  help  the  matter 
to  say  that  the  plate  in  both  groups  is  a  top  stem  joint  (centrodorsal),  for  the 
condition  of  the  plate  in  Cupres^Dcrlnm,  as  well  as  in  Myrtilocrimis,  is  very 
difTerent  from  that  under  which  the  centrodorsal  occurs  in  the  Apiocrinidtu, 
ComatuluB,  and  Ichthyocrinidao.  Wherever  that  plate  occurs,  it  is  in  dicyclic 
Crinoids,  and  the  infrabasals  are  fused  with  it.  When  the  fusion  is  complete 
there  appears  in  place  of  the  infrabasals  a  vacant  space  at  the  inner  floor  of 
the  calyx  between  the  basuls;  nothing  of  which  is  found  in  these  two  genera. 
Besides,  the  plate  does  not  rest  against  the  outer  faces  of  the  basals,  as  it 
should  do  if  it  were  a  top  stem  joint,  but  against  their  inferior  faces,  like 
the  infrabasals  of  true  dicyclic  Crinoids. 

Mr.  Bather  alludes  to  a  structural  peculiarity,  which  he  thinks  has  "more 
weight  in  the  classification  than  the  varying  extent  of  tegminal  develop- 
ment."  He  says:  "It  a  ill  be  seen  from  the  ensuing  remarks  on  Pisucriiius, 
Calceocnnus  and  Ilcrpctocrinus,  that  a  very  large  number  of  Inadunata  Mono- 
cyclica closely  resemble  one  another,  either  in  the  horizontal  bisection  of 
certain  radials,  a  character  which  in  Dicyclica  is  entirely  confined  to  the 
right  posterior  radial,  or  in  the  greater  development  of  certain  other  radials." 
He  overlooks  the  dicyclic  Tribrachiocriiuis,  which  has  three  compound  radials, 
and  we  find  on  examining  the  genera  which  he  referred  to  the  Monocyclica, 
that  among  the  twenty-four  only  eight  have  three  compound  radials,  and 
sixteen  have  not.  Among  the  latter  there  are  three  with  two  compound 
radials,  Anomalocrinus,  Ohiocrinua,  and  Bacrocrimis,*  and  three  with  a  single 

*  III  tlie  latter,  as  we  uudcrstaud  the  structure,  oul;  the  iufcrradiah  became  developed,  but  uut  tlic  arin- 
beariDg  section. 


8YSTKMATIC'   PART. 


150 


c^q;  tho  remnining  ton  gonora  liavo  simple  radiiili  tlironghout.  Neitlier  do 
wo  (iud  any  rLMiiarkiiblc  dovolopiuoiit  of  cortaiu  lii'lials,  oxccpt  when  IIr-mc 
ttro  compound.  All  tliis  is  soriouHly  in  tlio  way  of  inaiting  the  presence  or 
abHcnco  of  infnibaHals  a  Hnbonlinal  character. 

Bather  claims  tliat  among  the  Dicyclica  doparturos  from  tho  pcntamcroim 
Byminutiy  of  the  cup  plates  occur  only  in  tho  right  posterior  radial.  E\cop- 
tions  to  thi.H,  however,  are  found  in  AtdcstnrrinKH  ami  iVr(//"(v///»,«(,  in  wiiich 
tho  Hyminetry  is  disturbed  by  the  anterior  radial,  and  in  the  hitter  genu-i  by 
tho  right  antoro-latoral  together  with  the  anterior. 

Bather's  researches  were  largely  devoted  to  the  Dicyclica  of  the  Niagara 
and  Wcniock  age,  whidi  ho  divided  into  three  principal  families;  tho  '♦  Den- 
drocrinidfc,"  tho  "  Cyathocriiiidiv,"  and  the  "  Decadocrinida" ;"  and  in  addi- 
tion to  them  he  recognized  two  smaller  families,  the  "  Euspirocrinidu) "  and 
"  CarabocrinidoB,"  the  latter  imroprcsontod  in  Enrupo. 

The  Dendrocrinidio  are  defined  by  him  as  follows ;  "  Dicyclica,  with  li' 
alono,  or  with  anal  x  alone,  or  with  li'  and  anal  .c,  or  with  a  radinnnl,  anal 
X  and  one  plate  of  the  tube,  in  the  anal  area  of  the  dorsal  cup ;  with  broad 
radial  facet;  with  dichotomous  arms,  that  may  or  may  not  develop  pinnules; 
with  a  togmen  compo.sod  of  small  plates,  and  with  a  ventriil  tube  that  is 
unusually  long  and  transversely  flattened."  Ho  states  that  tho  family  is 
distinguished  from  tho  Decadocrinidio  by  the  continuous  dichotomy  instead 
of  tho  single  bifurcation  of  tho  arms ;  th.it  their  anal  x%  unlike  tlmt  of  (he 
Cyatliucrinidao.  is  always  associated  with  other  anal  plates;  that  the  radials 
have  a  wide,  slightly  specialized  flicet ;  and  that  their  tegmen  is  more 
delicate.  The  Dendrocrinidio  are  said  to  be  rei)rosented  in  America  in 
the  Hudson  River  group  by  Dimlrorrhuis,  in  tho  Devonian  —  both  in  this 
country  and  in  Europe  —  by  /fi))iiorriniis,  and  in  the  Carboniferous  by  I'liri- 
snrriiuix,  Potcn'orrlniis,  and  Srnp/ilncrlniis.  which  agree  in  the  structure  of  tho 
anal  area;  tho  three  latter  with  pinnulo.s.  tho  former  without  them.  'I'he 
presence  or  absence  of  pinnules,  and  the  structure  of  the  arms,  he  makes  the 
leading  characters  for  distinguishing  the  genera. 

lie  defines  his  second  family,  tho  Cyathocrinidnp,  as  having  "no  radianal 
or  tube  plato  in  tho  anal  area  of  the  dorsal  cvip ;  with  anal  .r  either  pros- 
ent  in  tho  cup  or  raised  above  it;  with  five  arms,  simple  and  dichoto- 
mous; with  tegmen  rather  solid."  Ho  refers  to  it  Ci/ti(/iorrin>is,  Gisuncrinua, 
and  their  descendants,  with  the  subdivisions  Cyathocrinito.s,  Achradocrinites 
and  Codiacrinitos,  of  which  the  latter  have  no  anal  at  all,  and  some  of  their 
gonora  have  an  inferradial,  or  a  radianal,  while  others  have  not. 


? 


1 


ICO 


TIIK  CUINOIDKA  CAMKIlArA   OF   NOIMIl   AMI.IMCA. 


The  Deciulooriniilii',  liis  third  fiiinil}-,  arc  (li'linutl  an  IoIIowh:  "  Dicyclica. 
in  wiiicli  tlic)  iinii.i  birurcato;  uaeli  iniiiii  braiu'ii  hoarin^  annlcts  ur  pinriih  ; 
with  from  iiutiu  tu  three  aiiul  phites  in  the  doixal  cu|),  Hiipportin^  ii  CiU"  >'• 
which  the  lunieii  is  uMuaily  llaltenoil  traiisvci'.Hely,  uiul  tiie  plates  piiea.  '  ' , 
with  a  tegmen  composed  of  niiinerous  Hiiiall  plates,  very  rarely  distinguish- 
able."  The  family  is  said  to  einbraeo  such  forms  as  Udtn/orriiiun,  Jhirij- 
erliiKs,  AlilcntocrinuH,  Sri/tnlopriiius,  and  finally  OucoerinuH,  Jiiijifir/ii/crinits, 
Ste>ii)iiiiti)rr!niis,  n\\i\  IJnrriints,  —  in  our  opinitm  the  most  hoterogom-ous  as- 
semblage of  genera  imaginable.  It  is  not  even  true  that  they  all  iiave  ten 
njain  arms ;  some  of  them  have  but  five,  others  seven,  nine,  twelve,  or  even 
fourteen;  and  these  modifications  apparently  occur  within  the  limits  of 
a  genus,  —  proof  enough  that  the  number  of  arms  is  a  most  unreliable  char- 
acter in  classification. 

Another  objection  is  that  the  family  includes  forms  with  pinnules  and 
uithout  them.  Bather's  views  respecting  the  pinnules  are  rather  peculiar. 
He  cxprcs.ses  the  opinion*  that  the  development  of  pinnules  by  itself 
cannot  bo  taken  as  a  character  indicative  of  divergence,  and  he  under- 
takes to  prove  this  by  the  genus  JJutrj/orriiiiin,  of  which  lie  a.«serts  that 
"  the  Swedish  species  have  armlets  and  not  pinnules,"  but  "  the  coimiion 
Dudley  species  undoubted  pinnules."  That  the  appendages  of  the  latter  are 
pinnules  and  not  arms,  he  probably  deduced  from  the  fact  that  the  branches 
of  this  species  arc  somewhat  smaller  and  arranged  regularly  from  alternate 
joints.  In  discussing  the  evolution  of  the  arms.  Bather  a.ssumed  t  that 
armlets  preceded  the  pinnules,  and  that  when  finally  the  armlets  became 
small,  ceased  to  branch,  and  wore  regularly  placed  on  alternate  sides  of 
successive  joints,  they  were  called  pinnules.  This  explanation  is  not  satis- 
factory, as  it  woidd  indicate  that  the  smaller  appendages  are  derived  from 
the  larger  ones.  It  seems  to  us  more  probable  that  the  arndets  are  true 
arm  branches  whoso  development  was  arrested ;  and  wo  believe  that  every 
species  o( Butri/ocn'niis  has  armlets,  and  that  pinnules  are  not  represented  in 
any  of  them,  liolrtjocrlnvs  dermhicti/his  we  take  to  be  morphologically  in 
a  similar  condition  to  Stetjannrriiiua  aruncohts  (Plate  LXI.  Fig.  2fl);  and  we 
think  that  in  both  of  them  every  joint  of  the  main  arms  bears  an  armlet, 
whereas  those  species  of  lio/n/orriinis  in  which  the  arndets  are  given  off  at 
intervals  are  in  the  condition  of  Stcfjaiiocrinux  ncitlptits  (Plate  LXI.  Fig.  1 «). 


•  Ann.  and  Mng.  Nat.  Hist.,  May,  1890,  p)'.  373-3/6. 
+  Ibid.,  p.  374. 


BY8TKMATIC  PART. 


161 


But  while  the  nrmlutH  of  the  Silurian  /.'  h-'mrinuH  bear  no  pinniilcM,  thono  ttf 
tliu  SiibciirboniroroiiM  Stitjaitorriniin  give  olT  pinnulon  from  the  iiruilctH, 

Uiithcr'.'*  cliwilicution  nml  tlicorioM  rowpecting  tin;  evolution  of  the  nrinH 
nro  open  to  many  critioiMinH,  and  aro  certainly  not  confirnuMl  by  a  ntudy  of 
the  Carboniferous  FiMtulutii.  lie  cannot  put  to;^etli('r  ccrtiiin  Poteriocrinidiv 
with  (ho  Dendroorinidu),  and  others  with  the  Dccadocriniiln',  nor  pliice  the 
non-pitnndato  Ilnmncnunn  nnd  Parinorriinia  in  a  family  with  piiuiide-bearing 
furmR.  Ilin  claHxification  Ih  based  principally  npon  two  things:  the  pre.xcnee 
or  absenco  of  infrabasals,  which  ho  makes  a  siibordinul  character,  and  tho 
relations  of  the  plates  at  tlu;  anal  side  among  tlieinsclvi's  and  (ownni  adjoin- 
ing plates,  npon  which  he  separates  the  families.  IK'  was  iicrliaps  not  awaru 
that  in  Uta-i/muiis  the  railianal  imiy  be  present  or  absent  in  the  same  specieH, 
and  that  Parinocn'iwa  would  bi'  substantially  identical  with  C'/iit/incriiiiis  but 
for  the  presence  of  tho  radianal.  As  family  characters  he  olso  relics  \ipon 
the  mode  of  branching  in  the  arms,  and  the  structure  of  the  tegmen,  which 
latter  he  has  been  able  to  observe  in  oidy  a  few  genera.  The  remarkable 
development  of  tho  posterior  area  into  a  ventral  sac,  which  in  1S!I0  was 
regarded  by  him  as  an  excellent  ordinal  character,  is  omitted  altogether  in 
his  present  classification. 

While  therefore  wo  cannot  agree  with  Mr.  Hathor  upon  bis  classification, 
wo  fully  acknowledge  the  excellence  of  his  specific  and  generic  descriptions 
in  his  late  work  on  the  Swedish  Inadunata,  and  the  many  fine  observations 
which  ho  has  brought  out.  Ilia  discoveries  npon  the  orientation  of  the  radials 
in  tho  Pisocrinida)  nnd  Calceocrinidni  are  of  tho  utmost  value,  and  have 
thrown  new  light  npon  these  difficult  groups. 

We  regard  as  tho  best  family  distinctions  among  the  Fistnlatn  tho 
presence  or  absence  of  infrabasals,  the  presence  or  absence  of  pinnules, 
and  the  relative  size  of  the  ventral  sac.  The  structure  of  the  tegmen,  if  wo 
knew  more  almut  it,  might  perhaps  also  afford  good  distinctions;  but  tho 
modifications  that  occurred  at  the  anal  side  of  tho  cup,  and  the  mode  of 
branching  of  the  arms,  can  be  utilized  only  for  distinguishing  genera.  The 
biscrial  arm  structure  did  not  obtain  a  foothold  among  the  Inadunata  imtil 
near  the  close  of  the  Subcarboniferous,  and  at  no  time  became  a  constant 
character.  More  important  for  generic  separation  is  the  mode  of  nnion 
between  tho  radials  and  brachials,  and  tho  form  of  the  facet  —  whether 
horse-shoe  shaped  or  forming  a  straight  line ;  also  the  form  of  the  ventral 
sac,  and  whether  one  or  more  of  the  radials  aro  compnnrru. 

SI 


(   . 


^ 


162 


THE  CRIXOIDEA  CAMERATA  OF   NORTH  AMERICA. 


The  least  tloparturo  from  the  structure  of  the  Larviformia  toward  the 
Fiatulata  is  fouiul  in  tiie  geiuis  Cumlocriims,  in  wiiich  the  toginen  is  com- 
pose<l  of  five  asyinniL'trical  orals,  meeting  laterally  and  by  their  inner 
ends,  four  of  theni  resting  against  the  rndials,  the  posterior  one  being 
separated  from  them  by  a  numljor  of  irregular  perisomic  pieces,  which 
enclose  a  short  anal  pyramid.  Somewhat  higher  difierentiatcd  is  the 
tegmen  of  C'/a/kicriinis  d/iifaciiis  Angelin  —  C.  rtimomis  Bather  —  (Plate  III. 
Fig.  (l),  whose  amliulacra  are  subti-gminal,  but  the  orals  are  separated 
from  the  radials  by  a  narrow  belt  of  perisome  ;  contrary  to  other  species  of 
Cjallmritius,  in  which  the  ambulacra  rest  upon  the  tegmen,  and  the  orals 
are,  or  seem  to  be,  in  a  state  of  resorption.  In  J/i/lincriiius,  the  ventral  sac  ia 
as  small  as  in  Cunibncninis,  and  it  has  large  orals  resting  against  the  radials; 
but  the  lateral  edges  of  the  plates  are  covered  by  the  SmnupliilkhtH.  The 
Cyathoerinidie  have  a  large  ventral  sac,  and  in  the  tegmen  a  niadreporite, 
which  was  prolnildy  unrepresented  in  the  Poteriocrinidic,  in  which  the  sac 
itself  is  perforatt'il.  The  ventral  sac  made  its  appearance  in  the  Ilybo- 
crinidie,  Carabocrinidie,  and  Anomalociinidie  as  a  very  insignificant  protuber- 
ance; in  the  ^leterocrinidiV,  Ik-leuniocrinirue,  and  especially  in  the  Cyatlio- 
crini(la%  ami  l'oteriocrinid;e,  it  attained  enormous  dinunsions,  but  dwindled 
down  in  the  En.'rinidtc  to  almost  nothing,  although  some  of  them  still  have 
well  defined  anal  plates.  We  do  not  restrict  the  ICncrinida;  to  forms  without 
anal  plates,  such  as  Encrinns,  S/rmiiititom'iiiis,  and  Fmocriiiiis ;  but  include 
among  them  the  genera  Eiijnirhi/rriniix.  Cromt/ncriiiiis,  Ciri'ncriiiii.s,  luid  Oitocriiuix, 
in  which  the  anal  area  passes  through  all  possible  transition  stages.  Vv'e 
make  the  reduced  size  of  ihe  sac,  and  the  higldy  diflerentiated  articulation 
between  the  radials  and  brachials,  the  distinctive  characters  of  the  fan\ily. 

The  Camkhata  constitute  a  compact  and  well  limited  natural  group,  and 
they  are  a  highly  specialized  type,  which  by  extraordinary  development 
reached  a  stage  of  extreme  difl'ereutiation,  and  produced  a  ventral  structure 
apparently  so  dilTerent  from  that  of  other  groups,  that  it  was  for  a  long 
time  found  impossible  to  homologize  its  plates  witli  those  of  the  other 
Crinoids.  They  represent  a  type  of  rapid  culmination  and  development, 
possessing  already  in  the  earliest  kncwn  forms  well  defined  pinnules,  and  the 
bise-ia!  arm  structure  in  most  of  their  families  i)eing  permanently  established 
at  the  close  of  the  Silurian.  The  organization  of  the  Camerata  may  not  bo 
intrinsically  higher  than  that  of  the  otiier  groups,  but  they  very  clearly 
represent  a  higher  state  of  development  than  Ilnplocriiiita  or  SjmlHilhocrinus, 


SYSTEMATIC   PART. 


1G3 


in  the  sense  that  Acfiiiocriims  is  n  more  ndvnnccd  typo  tlinn  Plaf^criiiiis.  Tlie 
two  former  represent  the  larval  state  of  the  Cainerata,  while  PMycriiius  is 
'I  sort  of  transition  form,  in  which  the  Camerate  stage  has  not  reached  its 
full  development. 

The  Camcrata  existed  at  the  beginning  of  the  Silurian,  and  survived 
to  the  close  of  the  Subcarboniferous,  with  a  feeble  reminiscence  in  tlie  Coal 
Measures.  But  although  they  developed  some  very  remarkable  and  short- 
lived forms  in  the  Silurian  —  such  as  the  Calyptocrinidtr?  and  Crotalocrinida^ 
—  the  type  is  pre-eminently  a  SubcarI)oniferous  one.  In  that  age  they 
reached  an  extraordinary  development,  not  oidy  in  the  abundance  with 
which  they  flourished,  both  as  to  numbers  and  variety,  but  also  in  extrava- 
gance of  form  and  size  in  every  one  of  their  leading  families.  In  the  lower 
Carboniferous  the  Camerate  type  .seems  to  have  achieved  the  summit  of 
its  possibilities,  for  extinction  followed  rapidly  after,  and  at  the  close  of  the 
Keokuk  epoch  there  was  scarcel}'  a  remnant  of  the  typical  section  left,  aiid 
at  the  end  of  the  Kaskaskia  the  whole  group,  so  far  us  Pala)ontology  informs 
us,  was  practically  extinct. 

The  Cainerata  fall  naturally  into  two  sections :  — 

I.  Those  in  which  the  lower  brachials  and  intcrradials  form  an  important 
part  of  the  dor.sal  cup. 

II.  Those  in  which  the  brachials  retain  the  form  and  small  size  of  arm 
plates,  and  the  intcrradials  are  almost  exclusively  confined  to  the  tegmen. 

The  first  of  the-'C  represents  the  typical  Camcrata,  of  which  an  Adinocrimts 
is  a  charaf'teristic  example.  It  includes  the  Reteocrinidnc,  Ivliodocrinida?,  Thy- 
sanocriuidaa,  Melocrinida\  Calyptocrinidie,  Batocrinidiv,  and  Aetinocrinida). 
This  section  reached  its  culmin.ition  among  the  Actiiiocrinidiu  in  the  genus 
Sh'otocrinus,  of  which  in  some  species  the  rays  are  incorporated  as  high  as  the 
twelfth  order  of  brachials. 

The  second,  or  non-typical,  section  represents  a  stage  in  which  the  modi- 
fication of  the  Inadunate  type  by  Camerate  tendencies  oidy  progressed  to 
a  limited  extent,  as  shown  by  PM>/criiiiis  and  allied  forms.  It  includes  the 
PlatycrinidiB,  Ilexacrinida),  Acrocrinido',  and  Crotalocrinidiu.  In  tiiis  section 
the  Camerate  type  was  not  perfectly  attained,  but  its  development  was 
checked.  This  may  have  been  duo  to  the  largo  .size  of  the  radials.  and  the 
comparatively  .small  size  of  the  succeeding  brachials,  which  retained  perma- 
nently the  condition  of  free  arm  plates.  The  species  of  this  group  are  inter- 
mediate bet  veen  the  Inadunata  and  the  typical  Camerata,  their  lower  arm 


^ 


i 


104 


THE  CRIXOIUEA  CAME" ATA  OF  NORTH  AMERICA. 


joints  taking  part  in  the  composition  of  the  calyx  by  nioana  of  plates  wliicli 
combine  the  functions  of  intoibrachials  and  interanibulacrals,  and  which, 
properly  speaking,  arc  plates  of  the  disk.  Another  peculiarity  characteristic 
of  this  section  is  the  presence  of  a  large  facet  upon  the  radials,  in  which 
tho_  lower  brachials  are  buried,  and  a  brachial  of  higher  rank  meets  the 
interradials,  and  sometimes  the  radials. 

The  question  has  been  asked  whether  the  Crotalocrinidiu  should  not 
be  placed  under  tiie  Inadunata,  instead  of  the  Canierata.  They  certainly 
represent  an  intermediate  form,  having  some  characters  even  of  the  Articu- 
lata.  But  their  lower  brachials  are  more  or  less  connected  with  plates  of 
the  calyx,  and  the  covering  plates  of  the  ambulacra,  imliku  those  of  the 
Inadimate  Crinoids,  are  rigidly  incorporated  into  the  tegmen.  They  are 
morphologically  in  the  same  condition  as  tlie  other  families  of  this  section, 
except  for  the  dicyclic  base,  and  represent,  as  we  conceive,  only  a  dilTerent 
degree  of  departure  from  the  Inadunatc  plan. 

The  typical  section  of  the  Camcrata  appears  to  have  been  the  first  in 
time.  It  was  well  defined  in  the  Lower  Silurian,  where  it  was  represented 
both  by  dicyclic  and  monocyclic  form.s, —  the  Khodocrinidas  on  the  one  hand, 
and  the  Batocrinidie  on  the  other.  They  flourished  about  the  same  period, 
cidminated  together  in  the  IJiu'lington  epoch,  and  disap|)eared  almost  simul- 
taneously, the  one  in  the  Keokidt  group,  the  other  in  the  Warsaw  limestone. 
In  the  Lower  Silurian  there  was  another  family — the  Reteocriuidiv  —  in 
which  the  structure  of  the  base  .seems  to  have  been  subordinate  to  other 
character!?,  and  we  found  it  advisable  to  include  among  them  monocyclic  and 
dicyclic  forms ;  it  was  short-lived,  not  enrviving  the  Hudson  River  group. 
The  Thysanocrinidai  and  Calyptocrinida),  the  former  dicyclic,  the  latter 
monocyclic,  came  to  light  in  the  I'pper  Silurian,  with  a  very  small  beginning 
for  the  former  in  the  Ihulson  River;  they  existed  for  a  time  in  considerable 
abundance,  but  perished  soon,  only  a  few  straggling  forms  surviving  to  the 
Devonian.  Of  the  monocyclic  families,  the  Melocrinidaa  were  the  earliest, 
ranging  from  the  Trenton  to  the  Hamilton,  where  they  seem  to  have  been 
abrujjtly  cut  oif.  The  other  great  monocyelic  family,  the  Actinocrinida;, 
appeared,  culminated,  and  disappeared  in  the  SubcarboniA-rcus. 

The  non-typical  .section  made  a  good  beginning  in  the  Upper  Silurian 
wi'l:  its  only  dicyclic  family  —  the  ephemeral  Crotalocrinida>  —  and  the 
iiatycrinidsD,  represented  by  five  genera,  of  which  four  ex])ired  before  the 
close  of  the  epoch.     The  surviving  Platycrinidaa  had  a  feeble  representation 


SYSTEMATIC  PART. 


105 


in  the  Devonian,  but  durinfj  the  Subcarboniferous  attained  in  the  genus 
ri(i///rriiiiis  a  wealth  of  forniH  wiiich  had  no  equal  before  or  afterwards  in  any 
other  group.  TIio  Htrugglo  for  exi.stence  was  kept  up  in  this  seetion  by  tlie 
IlexacrinidiT)  long  after  the  last  typieal  Canierate  Crinoid  had  disapiioared, 
and  the  expiring  effort  of  nn  exhau.sted  type  ia  seen  in  the  Coal  Mea.sureH  in 
the  form  of  the  diiuiiuitivo  Acrocriiiiis  Wuiiheni. 

It  appears,  therefore,  that  tlie  typical  Cainerata  do  not  represent  the  last 
of  them  in  point  of  time,  but  that  either  their  final  efforts  at  perpetuation 
were  carried  on  in  connection  with  a  tendenny  to  revert  to  the  luadunate 
type,  or  the  greatest  persistence  was  manifested  by  that  form  of  the  Came- 
rata  which  had  departed  from  it  the  least. 

The  change  from  the  pentamerous  to  the  bilateral  symmetry  consequent 
upon  the  introduction  of  an  anal  plate  into  the  ring  of  the  radials.  was  per- 
haps the  most  important  modification  that  took  place  during  the  j)aiieonto- 
logical  history  oE  the  Camerata,  and  it  occurred  within  tiie  range  of  our 
knowledge  of  the  group.  The  symmetry  of  the  dorsal  cup,  which  through- 
out the  Treuton  group  had  been  more  or  less  perfectly  pentamerous,  was 
disturbed  in  the  Hudson  River  group,  in  both  dicyclic  and  monocyclic  forms. 
In  the  former,  four  of  the  truncated,  heptagoual  basals  of  the  Rliodocriuida) 
were  retluced  to  pointed  hexagons  in  tiie  Tiiysanocrinidfe,  and  the  inter- 
radial  plates  .separating  the  radials  disappeared  from  four  sides,  that  at  the 
fifth  retaining  its  position,  and  serving  as  an  nnal  plate.  The  Rhodocriuidic 
were  a  loug-lived  family,  appearing  in  the  oldest  Silurian,  and  persisting  to 
the  climax  of  the  Camerata  in  the  Sulicarboniferous,  —  the  strange,  extrava- 
gant Gilhcrtnomuus  being  their  last  survivor ;  while  the  Thysanocrinidae 
scarcely  survived  the  Silurian. 

Among  monocyclic  forms  the  disturbance  of  symmetry  was  caused  hy  the 
interposition  of  an  anal  plate  between  the  posterior  radials,  which  converted 
their  pentagonal  base  into  the  liexagon  of  the  Batocrinidaj  and  Ilexncrinida). 
The  pentagonal  base,  though  reinforced  in  the  Niagara  by  the  (.iilypto- 
criniihu,  disappeared  from  the  typical  Camerata  with  the  Melocriuida'  in  the 
IlamiUon  ;  while  the  hexagonal  base,  with  its  accompanying  anal  plate, 
continued  with  great  vigor  in  tiie  Batocrinidap  and  their  offsiujot.  the  Actino- 
crinidiP,  througiiout  the  period  of  greatest  development  of  the  group,  and 
until  the  extinction  of  the  typical  section  in  the  Subcarboniferous. 

In  the  non-typical  section,  we  have  among  dicyclic  forms  no  example  of 
a  symmetrical  base,  the  Crotalocrinida)  having  n  truncated  posterior  basal 


I  I 


166 


THE  CRIXOIDEA  CAMERATA  OF   NORTH   AMERICA. 


aupporting  an  anal  plate.  But  among  monocyclic  forms  tlie  anal  plate  is 
unrepresented  in  the  Platycrinidae,  in  which  the  base  forms  a  pentagon. 
The  intr()(Uiction  of  the  anal  plate  occurred  in  the  Hamilton  group,  and 
produced  the  hexagonal  ba.se  of  the  Ilexacrinida).  The  two  groups  thence- 
forward flourished  side  by  side  to  the  middle  of  the  St.  Loui.s  group,  when 
the  Platycrinidie  became  extinct;  wiiile  the  Ile.xacrinidu)  and  their  oU'whoot, 
the  Acrocrinidae,  continued  until  the  extinction  of  the  Camerata. 

We  have  not  attempted  to  construct  a  genealogical  tree  for  the  Crinoids, 
or  a  brunch  of  one  for  the  Camerata,  because  such  representations  are 
generally  luisatisfactory,  and  in  this  case  the  tree  would  have  to  be  con- 
structed too  much  upon  imagination.  Besides,  our  task  is  an  Innnbler  one. 
We  have  rather  preferred  to  content  ourselves  in  this  respect  with  giving 
the  general  facts  which  our  investigations  seem  to  pretty  well  establi.sh,  and 
such  interpretation  of  them  as  appears  to  us  reasonably  consistent  therewith. 
Witiiin  these  limits  we  have  hoped  that  our  generalizations  may  help  to 
form  a  stable  foundation  upon  which  others  may  rai.se  more  ambitious 
structures. 

There  is  no  doubt  that  the  Crinoids,  by  reason  of  their  great  geological 
range,  and  capacity  for  individual  variation  due  to  their  complicated  struc- 
ture, offer  one  of  the  most  inviting  fields  for  demonstrating  the  principles  of 
evolution.  Tiiey  alTord  a  good  illustration  of  the  principle  that  individual 
development  fnids  a  parallel  in  a  general  way,  in  the  phylogenetic  history 
of  tiie  group.  But  while  recognizing  this  truth,  and  confirming  it  by  the 
many  interesting  proofs  which  our  studies  disclose,  we  must  beware  of  ex- 
pecting to  fnid  lineal  succession,  or  of  assuming  that  a  form  found  flourishing 
in  any  given  epoch  is  neces.sariiy  more  highly  organized  than  tho.se  occur- 
ring in  previous  epochs.  The  Palaeozoic  Crinoids  represent  in  a  broad  sen.se 
the  larval  stages  of  recent  Crinoids ;  but  there  are  many  ca.sos  in  which  the 
tendency  seems  to  have  been  one  of  retrogression  instead  of  progression. 
ILipiiicriiiii.s,  with  its  closed  pyramid  of  five  orals,  is  probably  the  most  primi- 
tive type  found  in  our  collections,  and  yet  it  is  a  Devonian  gcnu.s.  The 
great  family  of  the  Ichthyocrinidie,  whose  oral  condition  is  substantially  on 
a  par  with  that  of  many  recent  Crinoids,  occuired  abundantly  in  the  Silurian, 
it  is  also  iini)ossible  to  tell,  except  perhaps  in  a  very  general  way,  which  one 
of  a  number  of  variations  marked  the  line  of  succession ;  or  in  other  words 
which  was  for  the  time  being  the  racial  characteristic  carrying  all  others 
along  with  it,  even  though  many  of  them  may  seem  more  important.     For 


i  I 


SYSTEMATIC  PART. 


101 


the  snme  ronson  we  cannot  point  out  tlie  exact  coiisiin<,'uinity  (if  jrioiips 
wliich  are  apparently  related  by  one  or  more  characters.  For  we  liml  that 
when  a  type  starts  on  a  career  of  tlevelopincnt  on  a  specialiyxMJ  lino  iiiid 
runs  its  course,  other  characters  for  the  time  being  subordinated  tu  it  follow 
in  more  or  less  parallel  successions.  So  that  it  may  come  to  pass  that  at 
a  certain  time  we  find  two  types  apparently  belonging  to  dillerent  lines  of 
development,  which  have  reached  a  concurrent  condition  in  some  otlior 
important  character,  and  we  cannot  say  through  which  of  them  the  thread 
of  consanguinity  has  been  carried.  For  instance,  in  the  non-typical  Camerata 
we  have  the  Phitycrinidie  without  an  anal  plate  accompanied  and  succeeded 
by  the  Ilexacrinidac,  in  which  that  plate  is  present.  In  the  typical  section 
the  Melocriniihv)  are  followed  by  the  Batocrinida;  and  Actinocriniiliv  in 
similar  succession.  But  (according  to  our  pala'ontological  record)  the  sym- 
metric Platycrinidic  appear  at  a  somewhat  later  period  than  the  symmetric 
Melocrinidiu;  —  and  as  we  do  not  find  in  the  non-typical  suction  any  s^-m- 
metric  predecessors  of  the  Platycrinida\  we  would  bo  inclined  on  this 
ground  to  infer  that  they  were  derived  from  the  Melocrinida?.  But  here 
we  are  met  by  a  greater  difficulty,  for  this  involves  the  illogical  supposition 
tiiat  the  PiaiycriuidiD  —  a  family  of  the  least  development  of  the  Camerate 
type  —  are  derived  from  one  much  more  highly  organized  in  that  particidar 
line. 

The  trouble  is  that  all  our  generalizations  arc  necessarily  based  upon  the 
Crinoiils  as  they  are  represented  in  our  dikhcidiis,  and  not  upon  the  CViiioids 
as  they  actually  existed  in  geological  time,  which  is  a  very  dilTorent  thing. 
It  is  like  trying  to  reconstruct  a  book  from  detached  fragments  of  tin; 
chapters,  some  of  them  written  in  hieroglyphics  for  whose  decipherment  the 
key  has  not  yet  been  found,  ^\'e  are  accustomed  to  speak  of  the  imjicr- 
fection  of  the  geological  record,  but  it  is  doubtful  if  in  our  practical  studies 
wo  always  i)ear  in  mind  what  this  really  means.  To  say  nothing  of  the 
perio'ls  antedating  the  Silurian,  in  which  substantially  all  vestiges  of  lil'e  arc 
obliteraled  by  motamoiphisni ;  of  the  accumulations  of  fossilitVrous  strata 
which  have  been  destroyed  by  erosion  during  periods  of  elevation  of  the  sea 
bottom;  of  tlio  strata  which  over  three  fifths  of  the  earth  are  submerged 
beneath  the  ocean  ;  of  the  great  regions  unexplored,  or  covered  with  ice. 
snow,  or  snnd  ;  of  the  eciually  extensive  areas  in  which  tiie  fossililcrous 
rocks  of  one  formation  ore  buried  under  those  of  succeeding  ones;  —  leaving 
nil  this  out  of  con.sidcration,  how  much  do  we  actually  know  of  the  life 


? 


168 


THE  CKINOIDEA.  CAMEllATA  OF  NOUTII  AMElilCA. 


represented  in  the  rocks  accessible  to  «is?  Nearly  all  the  known  Sihirlan 
Crinoids  come  from  the  outcroppings  of  the  strata  at  two  localities  in  Europe, 
and  three  or  four  in  America.  The  Devonian  exj.  .<iu'es  producing  well 
preserved  specimens  are  even  more  limited.  The  Lower  Carboniferous  col- 
lections are  better  and  more  widely  distributed,  but  are  insignilicant  after 
all.  Take  the  Burlington  and  Keokuk  lime-stone.x,  wiiich  in  a  few  localities 
have  j)r()duce(l  more  Crinoids  in  number  and  .species  than  any  other  forma- 
tion. They  consi.st  of  several  hundred  feet  of  strata  almost  entirely  composed 
of  the  conuninuted  remains  of  countless  myriads  of  Crinoids  —  fragments 
which  are  worthless  to  tha  Palaeontologist.  It  is  only  rarely  that  a  thin 
layer  is  found  in  which  the  calcareous  skeletons  are  preserved  well  enougli 
for  study;  —  little  b  sin-  of  limited  extent,  in  which,  during  a  period  of  tem- 
porarily ([uiet  waters,  the  Crinoids  lived,  died,  and  were  imbedded  at  sudi- 
cient  depths  to  escape  the  detructive  effects  of  .shore  action.  If  the  collector 
hanpins  to  be  present  when  one  of  these  colonies  is  uncovered  by  the 
quarrymeii,  the  specimens  may  be  rescued  for  the  benefit  of  Science.  But 
it  is  an  oven  chance  that  they  will  be  buried  in  the  del)ris  of  Jn:  quarry, 
biokea  up  for  Ijallast,  or  walled  up  in  the  foundation  of  a  l)ui'.]ing,  and  thus 
h'>  lost  again.  Out  of  the  thousands  of  square  miles  in  which  these  rocks  lie 
nciros;  ilic  surface,  all  the  collections  th.at  have  ever  been  made  represent 
"  .i,  ;,i(e  imperfect  gleanings  of  not  more  than  a  few  acres.  If  it  l)e  sup- 
poyi.d  Ujat  v>e  get,  even  in  this  way,  a  fair  rcfiie.sentation  of  the  crinoidal 
life  of  that  period,  the  answer  is  that  .ilmost  every  new  discovery  of  "  nests" 
or  "colonies"  of  good  specimens  brings  to  light  new  forms,  and  that  species 
or  genera  hitlierto  very  rare  are  often  suddenly  found  within  a  limited  space 
quite  abundantly.  In  the  Upper  Coal  Measures,  to  judge  from  our  books 
and  museums,  one  would  suppose  that  Crinoids  were  well-nigh  extinct. 
Scarcel}'  a  dozen  species  are  known,  and  most  of  them  only  by  tlieir  lower 
calyx  plates.  Yet  there  are  many  beds  in  this  formation  which  extend  over 
iiundreds  of  thousands  of  square  miles  from  the  Missouri  Valley  far  into  the 
Rocky  Mountains  and  tilted  up  along  their  flanks,  which  are  completely 
fdled  with  fragments  of  Crinoid.s.  Suddenly  the  collectors  at  Kansas  City, 
who  have  studied  t'.i^-so  rocks  for  years,  discover  an  abundant  deposit  of  well 
preserved  specimens  in  a  shale  so  .soft  that  a  few  minutes  rain  di.ssolvcs 
them  into  unr  eogiii/.abic  fragments. 

The  importance  of  those  observations,  (('>  a  practical  matter,  is  sufficiently 
shown  by  the  f.-^ct  that  the  di.scove.-y  of  a  single  specimen  may  sometimes 


SYSTEMATIC   PAKT. 


169 


throw  new  light  upon  important  questions,  nnd  require  the  undoing  of 
much  previous  work  ;  —  us  was  iihistnvted  in  the  ease  of  the  disk  of  tiio 
IchthyocriniduB,  nnd  by  de  Loriol's  discovery  of  sninll  infrahasals  in  two 
Hpecies  of  Milkrici'intis,  which  made  important  changes  in  the  classification 
imperative. 

DKFIXITION   OF  THE  CKINOIDKA  AND  THEIU   PKIMAKY   DIVISIONS. 

Class  CUIN'OIDEA. 

Ecliinoderms  which  during  part  or  all  of  their  life  were  attached  to  other 
ol)jocts,  eitiier  l)y  means  of  n  stem  or  directly  by  the  abactinnl  side  of  tiic 
calyx.  The  vi.scoral  mass  enclosed  by  a  limestone  test  or  calyx,  constructed 
of  plates  symmetrically  arranged,  and  giving  off  well  defiiitd,  free  arms 
from  the  sides.     Mouth  directed  upwards. 

I. 

Crinoids  in  wliicli  tlic  arms  aro  free  alMive  the  radials.     Tlic  top 

joint  tilt!  youngpst  in  the  stem Orilor  Ixadv.nata. 

A.   l)isl{  composodot  orals  only.    Ambulacra  siibtogminal     Subordt-r  Larviformia. 
15.    Posterior  siilo  of  the  disk  extended  into  a  sac.     Am- 
bulacra suiira-tegminal Suborder  Fistulata. 


? 


f 


II. 

Crinoids  in  wliioh  the  lower  brachials  take  part  in  the  dorsal  cup. 
All  plates  of  the  calyx  united  by  close  suture.  Sloutli  and 
food-grooves  closed.    The  top  joint  the  youngest  in  the  stem. 


Order  Cameuata. 


III. 

Crinoids  in  which  the  lower  brachials  arc  incorporated  into  the 
calyx  either  by  lateral  union  witli  each  other,  or  by  supple- 
mentary plates,  or  a  calcareous  skin.  All  plates  from  the 
radials  up  movable.  Month  and  food-grooves  exposed.  The 
toj;  stem  joint  fused  with  the  infrahasals,  and  not  the  youngest 
joint  of  the  stem Order  Articulata. 

A.  Arms  non-pinnulate Suborder  Impinnata. 

B.  Arms  pinnulate Suborder  Pinnata. 

as 


170 


THE  CRINOIUKA  CAMKKATA  OK  NOUTll  AMKlilCA. 


CAMKUATA. 

Analytlt  of  the  Fuintllei, 

I.    TvncAii  Skctiov. 

Lower  brnclnals  and  interlxncliials  furiniiig  an  important  part  of  the 
dorsal  cup. 

A.  I.NTEKKADIALM    ILL  DKFINKD. 

The  lowiT  plates  of  tlit;  rays  luoro  or  less  completely  separated 
from  those  of  other  rays,  ami  from  the  primary  iiitcrrailials, 
by  irregular  supploinentary  pieces.  Aiuil  int(<rrn(lius  divided 
by  a  row  of  conspicuous  plates.    (Dicyclio  or  Monocyclic)      .         Ueteocrinid.k. 

B.  Intehkadials  well  ukkined. 

1.  Dkyixic. 

«.   llddidh  ill  I'onfiirt  ert'e/it  lit  the  pnnteriiir  shh' Tiiysanockinid.k. 

/).  liiidiidii  separated  all  iiiiiiiiid Uuouockinid.k. 

2.  JIONOIYCLII'. 

a.  Rtidiah  in  cmitnet  nil  nrniiiiil. 

Symmetry  of  the  dorsal  cup,  if  not  strictly  pentamorous, 
disturbed  by  the  introduction  of  anals  between  the 
brachials  only Melochinid.k. 

Arms  borne  in  eouipartment.s  formed  by  partiticuis  attached 
to  the  tegmen.  Dorsal  cup  perfectly  pentamerous.  I'lates 
of  calyx  limited  to  a  definite  number Calyptocrinmd.t?. 

b,  liiidiiih  in  rnnliiet  crcejit  at  the  posteeior  side,  irhere  the;/ 

are  se/mrnted  hij  an  anal  jdate. 

First  anal  plate  heptagonal,  followed  by  a  second  between 
,  two  interbr.ichials Batociuxid.k. 

First  anal  plate  hexagonal,  followed  by  two  interbrachials 
without  II  second  anal.  Arms  branching  from  two  main 
trunks  by  alternate  bifurcation Actixocrinid.i:. 


II.  Non-Tvpical  Section. 
Brachials  and  interbrachials  but  slightly  reprcHented  in  the  dorsal  cup. 

1.  MOXOCYCI.IC. 

a.  liadiah  in  eoiilaet  nil  nrniind.      Tinite  jientnrjnnal  ....  1'lATYCRINID.K. 

b.  Kadials  sejiii rated  at  jiosterior  side  by  an  anal  jilate.     Ilnse 

hexagonal. 

Hasals  directly  followed  by  the  radials ITexacrinid.k. 

Hasals  separated  from  radials  by  accessory  pieces  .     .  ArKocRiMD.i:. 

2.  DiCYCLIC. 

Kadials  in  eontaet  except  at  the  posterior  side Crotalocrinid.k. 


THE  CHINOIUEA  CAMKUATA  OF  NOKTII  AMEKICA. 


171 


GEOLOOICAL  AND  (lEOOllAI'HICAL   DISTItlld'TION   OV  TIIK  CAMEIUTA. 

Optu  flguiw  iDtllcftt*  Aawrlcan  HiwcIm,  tlioM  niarkvtl  ( } ,  KuropMo. 
NlMHKlt    OK  Sl'KC'lKH. 


OMiniL 


i  2 


Amtrlran. 


r|i|>i>t('>iul  MiMUiiireii 


Si.    l.cilliK 


Cppor 
:  l.iiwor 


Wiirmiw 
Ki'ukiik . 


lliirliiiRtciii  < 


KiiiilorliiHik 
Wavorl)' 
<  'liijiitt'iiii 
ChciniiiiK  . 
IlaniiltiMt 


I'piK'r  llelili'rlii'rK 
llrii<kaiiy    .     .     . 
I,imor  llc'lilorljorg 
Xiasam      .     . 
llllilsnli  Uivf'l- 


'I'roiitou 


TrncAt  rou. 


Moll*TTriCAL  Kt>UI. 


A|mn>xliiiiit« 
Kun)|N>iiii 

t^llllTttlvtlti. 


Miimow 


I  Miiiiiitaiii   I 
I  l.iiiin<tiiiiu  I 


I  TppiT        I 

I  Dcvuiiiaii  I 

Kiffl  .     . 


(irniiwac'kn 


(  Diiillov     I 
)  (iotlaiiil    ( 


Tiitnl  Ainerionn 


Total  Kiirojionii 


219 


Grand  Total  Speiiei 


683 


14(7) 


{'■>) 


80 
2(1!1) 


1  (.1)10(15) 


a 

1 

8 

8 

16 

.15 

54 


{7)(i:) 


33 


M 


(34) 


88 


(I) 


21(18) 


41 


(3) 


8(48) 


31 


(19) 


40 


(52) 


20.1 


18   ! 
(ilO) 


(20) 


81 


(4) 


(4) 


14 

(20)    (il) 
2H 


10 


(2) 


(24) 


■1(5) 


(.1.1) 


50 


(.13) 


'f\ 


i 


i:w 


Sim  III  \^. 

MT. 

Ml  i..'kui..k».iipvaiw  « 

r 

It 

ARIIKN- 

I 

jp 

I 

«iini>r.     I  |> 

HHtlltt. 

. 

1 

4       i       P       1      S 

r  ■  r 

f  1 

■5 

r 

3 

s 

4 

;  Si  ?■    ? 

i    K    !        a. 

rH  f 

r 
r 

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1 

f  g  £ 

• :  1:  r 

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^i| 

jz 

c*5 

w 

-" 

^ 

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HftfHM-rliiMM*. 
Kti<N|<irriulilM. 

CulyitttK-rliililu. 

lUttN-riiitdM*. 

ArllnocriuldM. 

? 

p 

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^ 

- 

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t'roUlwriuldM. 
llstyrrliiidM. 

MnwrliiltlAf. 
AirocrliiUlnc. 

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^^ 

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r 

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('ii|iri<wMKTliiUi. 
MyrtilliH-riiiiii. 

Mil|ll'KTllltlH. 

HyiiiKiillKHTlnui. 

AllnKtHrlliiiii. 

I'lMHTlnill. 

- 

* 

! 

^ 

'     " 

HylNxrliiltUr. 
HfUTorrliiUlae. 

(.'iltillmrliiUlM. 

Itt'lfiiiliorrliililM, 

OimtrriN-niiililut. 

Cyallnxrliii.Iiir. 

? 

^ 

► 

— 1 

1 

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— , 

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g 

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m 

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— 

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Aiitylnt'rinltliic. 

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1 

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w^ 

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3 


B.    Dincrij)tii'e. 
nr/rKOCRIXIl).K  W.  and  Sp.  (1885). 

ThB  LOWKR  PLATKS  111'  TIIK  IIAYH  MOrtK  oil  I.KSH  C'OMI'LCTKLY  HEPAUATEt)  FUOM  THOSE 
OK  OTIIEIl  HAVS,  AM)  EUciM  TIIE  PIIIMAIIV  INTKIiriAIII  Al.H,  nV  lllllElil'LAIl  HUPPLK- 
MKNTAKV  PIECES.  ANAL  IN TEllllAIUrs  IHViDEI)  IIY  A  VKIITUAL  ItOW  OF  CdN.SPICII- 
POUS   PLATES.      (DltyCLIC   Oil    MoNOlVt  Lie.  ) 

Aimh/'Oi  "J'flir  Oiiiirn, 
Arma  uulserlal. 

"■     Il'dllldh  Hf/i  ill  iii'iiiiikI. 

J)iii/i'/!i:  i,iip,iHiil»  5.     ('oluiiin  |H'iit;iiigiilir RKTEoruiNM's. 

Muiiiii\i/i'/ir.     Ilasiils  l.    Cdluinii  siniaro Xemukim  m. 

A.    Jiiitlltt/i  nr/ittrntiil  niilij  nt  iiiiiit  »!i/i: 

Monoei/rllc.     HiiNals  ">.    ('Dlumii  obscurt'ly  ju'iitangular Ta.naocui.vun. 

Gfnfdijlfal  mill  (Jioifrn/i/uriil  Dlslrlliiittoit 
Number  of  known  apedea.      Only  known  In  America. 


Formation. 

neTKorniMii^. 

AmiTiiiui. 

lliulsuii  liivur. 

Hcteoorimis. 

Xciiooriiius. 
2 

Tanaocrinus. 

3 

1 

'rreiitoii. 

1 

- 

Total  »p«Im  ...  7 

4 

2 

1 

? 


Rcmtii'ls.  —  Tliis  family  was  e.ttnl)lislie(l  to  roocive  a  littlo  group  of  rx)\ver 
Silurian  Crinoids,  (li.xtitijfiiislii'd  from  all  otiicr  known  forms  by  the  irregulr.r- 
ity  and  ab.sonce  of  definite  arrangement  in  the  intenadial  plates,  caused  by 
tije  intercalation  of  minute  supplementary  pieces.     These  small  pieces  were 


i     ^ 


IMAGE  EVALUATION 
TEST  TARGET  (MT-3) 


1.0 


1.1 


£   U£    12.0 


m 


||L25  |||,.4   ,J4 

^ ' 

6"     

► 

Photographic 

Sciences 
Corporation 


23  WIST  MAIN  STREET 

WEBSTER,  N.Y.  M5S0 

(716)  •72-4S03 


0 


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.^i^ 


^A' 


4^' 


174 


THE  CKINOIDKA  CAMEBATA  OF  NORTH  AMERICA. 


Oaiiio^ 


introduced  in  the  growing  Crinoid  in  great  numbers  among  the  primary 
interradials  and  interdistichals,  and  between  these  and  the  basals,  radials, 
and  brachials.  The  interrndial  and  interdistichal  spaces  throughout  this 
group  are  greatly  depressed,  and  the  plates  succeeding  the  radials  folded 
into  conspicuous  ridges.  This  structure,  combined  with  the  more  or  less 
rudimentary  character  of  the  interposed  plates,  is  so  unique  and  remarkable, 

that  all  other  characters,  some  of 
which  in  other  groups  are  charac- 
teristic of  very  distinct  families, 
appear  to  be  subordinated  to  it, 
and  we  are  compelled  to  unite 
under  this  family  both  monocy- 
clic and  dioyclic  forms;  those  in 
which  the  radials  are  all  sepa- 
rated, and  those  in  which  they 
are  in  lateral  contact  at  four  sides. 
We  think  that  few,  after  seeing 
a  large  number  of  specimens,  will 
doubt  the  propriety  of  this  course ; 
for  the  structure  in  question  pro- 
duces a  habitus  so  distinct  and 
predominant,  that  it  is  only  by 
means  of  these  characters  that  the 
three  genera  of  this  family  can  be  separated. 

In  our  classification  of  1885,*  we  proposed  the  genus  Canistrocrinus  upon 
two  species,  which  according  to  the  descriptions  differed  from  all  genera 
previously  known.  In  defining  the  genus  we  relied  upon  the  correctness  of 
the  figures ;  but  these  have  proved  to  be  mi.sleading  in  some  very  important 
points,  and  we  are  compelled  to  withdraw  it.  As  to  "Canistrocrinus"  liichard- 
soni  {Glijptocrimis  liichardsoni  Wetherby).  we  are  now  convinced  that  it  is 
a  Ghjidocrimis,  and  identical  with  Gl///)focriiius  siibglohosiis  Meek.  It  has  well 
defined  interradials,  aiul  the  anal  plate  rests  vpon  the  radials,  and  not  between 
them.  The  other  species,  ^'Canistrocrinus"  Pattcrsoni  {Gli/ptocrimis  Puttersoni 
S.  A.  Miller),  may  also  prove  to  be  a  Oli/ptocrinus.  The  type  specimens, 
which  Mr.  Miller  was  kind  enough  to  send  us  for  comparison,  are  not  in 
a  condition  to  make  out  the  structure  satisfactorily,  being  covered  to  a  large 


Fig.  0.     Reteocriiiiis  Oiiealli. 


Revision,  Part  III.,  p. 


reteocrinid.t:. 


175 


extent  by  hard  matrix;  and  we  are  unable  to  say  at  present  to  what  genu.s 
they  belong. 

S.  A.  Miller,  in  his  arrangement  of  the  Lower  Silurian  Camerata  in 
1883,*  united  lidcocnnus  and  Xeiiocriiiiis  with  Arc/iavcriniis,  CnjHtlucrliiiis, 
Gli/ptastcr,  Gli/ptocrimis,  and  Lampterocriims  in  one  fiiniily,  under  the  "  Gi^pto- 
crinidae."  It  is  not  clear  to  us  upon  what  this  classification  wiu  based,  since 
the  author  did  not  discriminate  between  the  presence  or  absence  of  infra- 
basals  as  a  family  distinction,  nor  between  a  regular  or  irregular  arrange- 
ment of  the  interradials ;  nor  did  he  give  attention  to  the  structure  of  the 
anal  side,  upon  which  most  writers,  and  Miller  himself,  have  relied  for 
excellent  family  characters.  In  a  later  paper  on  Gli/ptocrimis  and  allied 
forms,t  he  states  that  the  presence  or  ab,sence  of  "  .subradial "  plates,  the 
presence  or  absence  of  "  secondary  radials,"  the  structure  and  form  of  the 
column,  and  the  presence  or  absence  of  a  "  proboscis,"  are  the  principal 
characters  upon  which  "  the  genera  of  this  special  group  "  have  to  be  separ- 
ated. All  of  these  rules  are  in  a  greater  or  less  degree  infringed  by  Miller 
himself.  His  "  Gl^piocrintis  "  parvus  has  infrabasals  ;  his  ^'Ghjptocn'ntts  Forn- 
shelli,  a  pentangular  stem  instead  of  round  as  in  the  typical  species.  A  "  pro- 
boscis," such  as  occurs  among  the  Actniocrinida?,  does  not  exist  at  all  in  this 
group,  or  at  least  has  not  been  observed.  Neither  do  we  find  that  the 
proximal  distichals  are  ever  free  arm  plates,  as  Miller  claims  to  be  the  case 
m  "  Pi/cnocrimmy  The  specimens  which  he  refers  to  this  genus,  and  which 
he  kindly  sent  us  for  comparison,  have  from  one  to  two  interdistichals,  and 
necessarily  had  "  secondary  radials." 

In  Miller's  classification  of  1889,  |  the  "  Glyptocrinidoe "  embrace  the 
genera  Archccocnnus,  G/>/ptocii'niis,  Compsoeriniis,  Pi/cmcnims,  and  Schkocriims, 
which,  as  we  think,  are  representatives  of  almost  as  many  families.  He 
there  makes  Xcnocrlnus  the  type  of  a  distinct  family,  refers  Glyptasfcr  and 
Laniptcrocrinits  to  the  Glyptasteridte,  and  places  Gauroeriiiiis,  Ihieocrinvs, 
Raphanocrinus,  and  Thi/samcrimis  under  Gaurocrinidae. 

The  Reteocrini<la}  are  restricted  to  America,  where  only  seven  species 
have  been  discovered. 


^ 


I  •■ 


I  !> 


•  Amer.  Palffioz.  Foss.  (od.  2),  p.  278. 

t  Dec,  1883;  Journ.  Cinciii.  Soc.  Xat.  Hist.,  pp.  218-219. 

X  North  Amer.  Geol.  mid  Pnlreoiit.,  pp.  211  to  215. 


/ 


176 


THE  CRINOIDEA  CAMERATA  OK  NORTH  AMERICA. 


RETEOCRINUS  Uilli.vgs. 

1859.    E.  Billings  ;  Geol.  Rep.  Caiindn,  Decade  VI.,  p.  03. 

1S81.     \V.  niul  Sp.  ;  Ucvision  I'ulieocr.,  I'liit  11.,  p.  101  (Proceed.  Aend.  Nnt.  Sci.  Philii.,  p.  305). 

1883.     P.  II.  Caiu-extei<  j  Pjil.  Tniiis.  Uo.vul  Soc.  (Pail  III.),  pp.  92U-932. 

1883.     W.  and  Sp. ;    '  mer.  Jourii.  Sci.  and  Arts,  Vol.  XXV.,  pp.  255-208. 

1883.     S.  A.  MiLLE    ,  ibid.,  pp.  105  to  113. 

1885.     W.  and  Sp.  ;  Revision  Puteocr.,  Part  III.,  p.  87  (Proceed.  Acad.  Nut.  Sci.  Pliiln.,  p.  309). 

18S9.     S.  A.  Miller;  North  Anicr.  Geol.  and  Palroont.,  p.  277. 

Svn.  UtyplocrtHus  (m  part)— Hall;  1872,  2itb  Hep.  N.  York  State  Cab.  Kat.  lli»t.,  \>.  200,  Plate 
5,  Pigs.  18  &  19. 

Svn.  Glyptocrinm  (in  part)  —  Wetiieuhy  ;  J.inrn.  Ciiiein.  Soc.  Nat.  lli.st.,  Vol.  II.,  Plate  10,  Fig.  1. 

Sj'i.  Gli/ptocrinua  (m  part)  —  S.  A.  Miller;  1881,  Journ.  Ciiieiu.  Soc.  Nat.  Hist.,  Vol.  IV,  p.  83, 
Plate  1,  Fig.  5,  and  1881,  il)id.  Vol.  VI.,  p.  227. 

Syu.  Oaurocrinus {m  part)  — S.  A.  Miller;  1883,  ibid.  Vol.  VI.,  pp.  228,  229. 

Calyx  obconical,  its  .symmetry  decidetJly  bilateral,  interradial  and  inter- 
distichal  spaces  profoundly  depressed ;  the  plates  all  along  the  rays  distinctly 
folded,  so  as  to  produce  strong,  rounded  ridges  upon  their  outer  surfaces, 
and  deep  grooves  at  the  inner.  The  ridges  branch  upon  the  axillaries,  and 
follow  the  distichals  to  the  arm,^  Other  branches  proceed  from  the  middle 
of  ihe  radials  to  adjoinin;.^  basals. 

Infrabasals  five,  variable  in  size ;  sometimes  barely  protruding  beyond 
the  column.  Basals  five,  large,  protuberant,  hexagonid,  the  upper  angles 
truncated,  and  the  ends  somewhat  inflected  to  meet  the  deep  depressions  of 
the  interrad'al  spaces.  Eadials  separated  all  around,  sharply  angular  at  the 
lower  faces.  Costals  two  to  three ;  their  axillaries  clo,sely  resembling  the 
radials,  but  angular  above  instead  of  below.  Distichals  numerous ;  all,  or 
nearly  all  of  them,  take  part  in  the  calyx,  and  the  upper  ones  retain  the 
form  of  free  arm  joints.  The  proximal  pinnule  occurs  on  the  second  dis- 
tichal.  Arms  ten  at  their  origin,  but  generally  bifurcating;  composed  of 
rectangular  or  slightly  cuneate  pieces.  The  interradial  and  interdistichal 
spaces  filled  by  primary  and  secondary  plates  ;  the  latter  very  minute,  inde- 
finitely arranged,  ill-formed,  and  interposed  between  the  others,  and  along 
the  sides  of  the  ba.sals,  radials,  and  brachials.  The  anal  interradius  wider,  and 
longitudinally  divided  into  two  equal  parts  by  a  row  of  very  prominent  anal 
plates,  which  lie  in  a  straight  line  from  the  basals  to  the  anal  opening. 
Ventral  disk  depressed  convex,  composed  throughout  of  minute  irregular 
pieces,  which  form  a  continuation  from  the  interbrachials  and  interdistichals. 
Ambulacra  subtegminal;  Anal  opening  excentric,  at  the  top  of  a  small 
protuberance.  • 

Column  large,  pentagonal ;  the  axial  canal  of  medium  size. 


Ill 


RETEOCUIXID^E. 


■  (  t 


Distribution.  —  Age  of  the  Trenton  and  HudHon  river  groups.  Restricted 
to  America. 

Remarks.  —  According  to  Billings,  the  calyx  of  Hdcocriims  stclluris,  the 
type  of  the  genus,  consists  of  a  reticulated  skeleton,  composed  of  incomplete 
or  rudimentary  plates,  each  consisting  of  a  central  nucleus,  with  three  to 
five  stout  processes  radiating  from  it.  Of  such  plates  he  describes  three 
rings  of  five  each,  corresponding  in  position  with  infrabasals,  basals,  and 
radials  of  other  Crinoids,  and  he  states  that  the  genus  in  general  structure 
agrees  with  Cyathocritms,  Dcndrocrinns,  and  allied  forms. 

It  would  seem  at  first  sight  that  this  description  docs  not  apply  to 
"  Glypiocrinus  "  Oncalli  and  the  other  species  that  have  been  referred  to  this 
genus,  as  they  have  numerous  interbrachials  and  interdistichals  Avhich  Bil- 
lings failed  to  notice.  These  plates,  however,  are  actually  present  in  the 
type  specimens,  having  been  exposed  by  additional  cleaning.  Looking  at 
Reteocrinus  Oncalli  in  its  usual  preservation,  with  its  deep  intorradial  areas 
covered  by  matrix,  it  corresponds  well  with  the  original  description.  The 
specimens  in  that  state  seem  to  have  but  three  rings  of  plates  in  the  calyx, 
and  free  brachials  from  the  radials  up. 

Miller  refers  to  Reteocrinus  only  Billings'  two  typical  species,  placing  the 
other  three  under  Gmirocrinus.  We  cannot  discover  any  ground  for  generic 
separation  of  the  Ohio  and  Canada  species.  It  is  true  Reteocrinus  stclluris  has 
a  third  costal,  but  Miller  himself  did  not  attach  much  importance  to  this 
character,  for  he  grouped  Reteocrinus  Jimhriatus  with  but  two  costals,  along 
with  R.  stelluris,  which  has  three. 

In  amending  the  genus  Reteocrinus  in  1881,*  we  referred  to  it  the  follow- 
ing species :  Gli/ptocnmis  Bacri  Meek,  Glyptocrinus  cognatus  Miller,  Reteocrimis 
Jimbriatus  Billings,  Reteocrinus  gracilis  Wetherby,  Glgptoerimts  Oncalli  Hall, 
Ghfptocrinus  Richardsoni  Wetherby,  and  Reteocrinus  stellaris  Billings.  We 
afterwards  f  withdrew  Reteocrinus  Buei-i,  which  we  found  to  be  a  Xenocrinus, 
and  Reteocrinus  Richardsoni,  which  we  placed  under  Canistrocrinus ;  and  we 
added  Gaurocrinus  magnijieus  S.  A.  Miller.  Reteocrinus  cognatus  is  probably 
a  large  R.  Oncalli,  and  R.  gracilis  a  synonym  of  Ptychocrinus  parvus. 

*  Revision,  Part  II.,  p.  102. 
t  Hcvisiou,  Part  III.,  p.  96. 


m 


? 


J| 


;' 


178 


THE  CRIXOIDEA  CAMERATA  OF  NORTH  AMERICA. 


ReteocrinUB  StellariS  Billings. 
Plate  IX.  Fiffs.  3a,  b,  c. 

1830.  E.  BiLLiNcs;  Gen!.  Ufp.  Ciiniuk,  Decade  IV.,  p.  61,  Pluto  9,  Figs.  4a,  b,  e. 

1877.  S.  A.  MiLLEli;  Ciilal.  Aiiier.  i'ulicoz.  Foss.,  p.  90. 

1881.  W.  and  Sp.     llevisioii  Pala^ocr.,  Part  IT.,  p.  193. 

1889.  S.  A.  Millek;  North  Aiiier.  Geology  aiid  ralieoiit.,  p.  277. 

Calyx  proportionally  larger  than  in  any  other  species  of  the  genus, 
embracing  all  the  distiohals  and  portions  of  the  palmars. 

Infrabasals  and  basals  uuiisually  large ;  the  former  projecting  distinctly 
beyond  the  column,  each  plate  forming  a  good-sized  pentagon.  Basals 
heptagonal,  slihtly  truncated  and  folded  inward  at  the  upper  ends;  four 
of  them  of  equal  size,  that  facing  the  anal  side  larger,  and  the  truncation 
wider.  The  surface  of  the  basals  is  marked  by  prominent  keel-like  pro- 
cesses, meeting  in  the  centre  of  the  plates ;  one  of  these  proceeds  to  the 
radials  and  costals,  two  others  to  the  infrabasals.  At  the  sides  of  the  pro- 
cesses there  ai'e  deep  depressions,  five  of  them  in  a  radial  direction,  formed 
l)y  the  inflection  of  the  lower  angles  of  the  radials  and  the  upper  lateral 
margins  of  the  basals;  five  others,  somewhat  smaller,  triangular  in  outline 
and  interradial,  by  the  basals  and  infrabasals.  The  posterior  basal,  at  its 
upper  face,  has  three  ridges  instead  of  two,  of  which  the  median  one  is 
continuous  with  that  formed  by  the  anal  plates.  Radials  about  one  half 
longer  than  the  co.stals.  Costals  three ;  the  first  and  second  quani-an- 
gular,  the  third  pentangular.  Distichals  five  to  seven  or  more,  decreas- 
ing in  width  upwards,  the  upper  ones  taking  the  form  of  free  arm  plates. 
Above  the  distichals  are  two  more  divisions,  but  only  a  few  of  the  palmars 
take  part  in  the  calyx.  The  arms  are  extremely  short,  and  taper  rapidly ; 
they  are  composed  of  rather  long,  quadrangular  joints.  Interbrachial  and 
interdistichal  areas  profo'mdly  depressed,  paved  by  numerous  irregularly 
arranged  and  ill-formed  pieces,  with  a  slightly  stellate  surface.  Anal  in- 
terradiu.s  twice  as  wide  as  the  others;  divided  by  a  longitudinal  row  of  anal 
plates,  somewhat  narrower  than  the  costals,  but  resembling  them  in  height 
and  curvature.  Construction  of  tegmen,  position  of  anal  opening,  and 
arrangement  of  pinnules  unknown.  Column  obscurely  pentangular,  at  the 
upper  end  composed  of  very  thin,  knife-like  joints. 

—  Horizon  and  Localiti/.  —  Trenton  limestone ;   City  of  Ottawa,  Ontario, 
Canada. 

Our  figures  were  made  from  the  ti/pe  specimens  in  the  Canada  Survey 
Museum. 


RETEOCRIMD.K. 


179 


Reteoorinus  flmbriatus  Uillinus. 
Plate  IX.  Fig.  4. 

1859.  E,  Billings;  Gcol.  Rep.  Caiiiuln,  Dec.  IV.  p.  05,  Plato  9,  Fig.  3. 

1877.  S.  A.  Miller;  C'lital.  Aincr.  I'alieoz.  Foss.,  p.  DO. 

18S1.  W.  and  Sp.i  Uevisioii  riiljcocr.  I'art  U.,  p.  193. 

18S3.  W.  niul  Sr. ;  Amcr.  Joiiru.  Sei.,  Veil.  XXV.,  j).  Sfifi. 

1889.  8.  A.  Miller;  Nurtli  Aiiuir.  Gcol.  &  I'alicout.,  \i.  277. 

A  small  species  of  the  type  of  Relcocrhnis  maz/iii/ciis.  Dor.<!nl  cup  to  the 
top  of  the  costals  subpyramidal ;  .slightly  more  spreading  from  there  upward. 
The  plates  forming  the  rays  rounded,  and  elevated  conspicuously  above  the 
interradial  spaces. 

Infrabasals  Ptnall,  their  upper  angles  and  the  adjoining  lower  angles 
of  the  basals  depressed  into  small  pits  surrounding  the  column.  Similar 
pits  are  formed  in  a  radial  direction  by  the  basals  and  lower  margins  of  the 
radials.  Costals  two,  as  large  as  the  radials.  Distichals  eight  or  more, 
narrower  than  the  costals,  the  lower  one  longer  than  wide,  the  length  of  the 
succeeding  ones  gradually  decreasing  upwards.  Six  of  them  apparently  are 
included  in  the  calyx,  the  others  free  arm  plates.  The  upper  distichal  is 
axillary,  and  .supports  two  arm.",  one  of  which  remains  simple,  while  the  other 
bifurcates  once  more.  The  arms  decrease  but  little  in  size ;  they  are  cylin- 
drical, composed  of  rather  long  pieces,  quadrangular  in  outline,  with  nearly 
parallel  faces.  Pinnules  decidedly  tapering  to  their  distal  ends.  Inter- 
radial spaces  deep,  paved  by  a  large  number  of  very  small,  slightly  convex 
pieces,  without  definite  arrangement.  There  is  generally  but  one  plate  in 
contact  with  the  basals,  but  its  outlines  are  very  irregular,  and  that  is  still 
more  the  case  with  the  succeeding  plates,  and  the  numerous  interdistichals. 
Form  of  ventral  disk,  and  construction  of  the  anal  sjde  unknown.  Column 
at  its  upper  end  sharply  pentagonal,  with  re-entering  angles. 

Horizon  and  Lomliti/.  —  Hudson  River  group ;  Charleton  Point ;  Anticosti. 
Ti/jK  in  the  Canada  Survey  Museum. 


I  i 


^ 


!  i 

M' 


Beteocrinus  Nealli  (Hall). 

Plate  IX.  Figs.  la-f. 

1872.  Qlyptocrinui  Nealli  —  Hall  ;  S-tth  Rep.  N.  Y.  State  Cab.  Nat.  Hist ,  p.  206,  Plate  5,  Figs.  18  &  19. 

1S73.  Gli/ptocrinus  Onealli  —  Meek;  Geol.  Rep.  Oliio,  Palrcniit.,  I,,  p.  34,  Plate  2,  Figs.  3ff,  b,  c. 

1881.  Rcleocrinus  Onealli  —  W.  and  Sp.;  Revision  Palicncr.,  Part  IT.,  p.  193. 

1S82.  Glyptocriiius  Nealli  —  S.  A.  Miller;  Jouni.  Ciiiein.  See.  Nat.  Hist.,  Vol.  V.,  p.  37. 

1883.  Ke/eorrimia  Oiienlli  —  'W.  and  Sp.  ;  Amer,  Jmirn.  Sei.,  Vol.  XXV.,  p.  2fiO. 

1883.  Gaurocrinm  Nealli  —  S.  A.  Millea;  Jouru.  Ciucin.  Soc.  Nat.  Hist.,  p.  229. 


!     i 


I. 


.]t 


180  TIIK   CUINOIDKA   CAJIhRATA   OF   NORTH   AMERICA. 

1885.     Ri'IrorriiiuH  n,i,;i/li—W.  mid  Sr. ;  Hcvisi  )n  Piilu'orr.,  I'nrt  III.,  |i.  80. 
18S9.     (luurofriiius  Xeulli — S.  A.  M11.1.BU;  Ncrtli  Aiiicr.  tleol.  &  I'liliuoiit.,  p.  2-17. 

S^il.  Glj/iilcn'i-iiiiiH  cwjiMtna  —  S.  A.  M'LLEli;  ISbl,  Ciiiciii.  Juurii.  Nut.  llist.,  Vol.  IV.,  p.  75,  I'liite 
1,  Fih'S'  5.  5''' 

Syn.  Gdiirucriiiun  cogniitus  —  S.  A.  Mii.lkr;  18S1,  Ciueiii.  Joiirii.  Nat.  llist..  Vol.  VI.,  p.  22'J. 

Syii.  Itilruvriiimi  co(jmUiis — \V.  1111  i  Si',  j  1881,  UcvisiuU  I'ula'ocr.,  i'liit  11.,  p.  11)3. 

Calyx  obconical ;  intorrad.ivl  and  intoraxillary  spaces  deeply  depressed, 
producing  a  pentagonal  oiitiinu  below  the  distichuls,  and  decogonal  above 
tlieni. 

Infrabasals  small,  but  projecting  beyond  the  column.  Basals  large,  their 
lateral  margins  deeply  impressed,  forming  an  elongate  pit  in  which  the  upper 
angles  of  the  infrabasals  and  the  lowei'  angles  of  the  radials  are  involved. 
The  radials,  costals,  and  lower  distichals  are  folded  abruptly  inward,  their 
sides  extending  to  the  bottom  of  the  interradial  and  interdistichal  spaces, 
leaving  a  very  narrow  surface  expo.sed,  not  more  than  the  width  of  the 
arms.  Distichals  ten  to  fourteen,  of  which  six  to  seven  are  located  within 
the  calyx  walls,  the  others  free.  Of  the  fixed  plates,  the  three  or  four 
proximal  ones  are  larger  and  especially  longer  than  the  succeeding  ones, 
which  are  nearly  as  short  as  the  free  plates.  A  second  bifurcation  takes 
place  in  the  free  arms,  giving  twenty  arms  to  the  species.  Arms  long, 
cylindrical,  gradually  tapering,  and  composed  of  short,  wedge-formed  pieces. 
The  first  pinnule,  which  is  given  off  from  the  second  disticlml,  is  moriB  erect, 
and  considerably  stouter  than  any  of  the  rest.  The  second  pinnule,  which 
occurs  on  the  opposite  side  at  the  fourth  plate  (the  third  bears  no  pinnule), 
is  smaller  than  the  first,  but  larger  than  the  third,  which  is  of  the  ordinary 
size.  The  three  proximal  pinnules  are  incorporated  into  the  calyx,  the 
succeeding  ones  free.  Interbrachials  and  interdistichals  very  numerous, 
exceedingly  small,  and  of  very  irregular  form  and  size ;  the  marginal  pieces, 
as  a  rule,  being  smaller  than  the  others.  Anal  side  marked  by  a  conspicuous 
median  ridge.  Tegmen  low-hemispherical,  decagonal  in  outline ;  the  spaces 
overlying  the  food  grooves  .slightly  elevated.  Anal  opening  excentric,  almost 
marginal,  placed  in  the  middle  of  a  small  protuberance.  Column  pentan- 
gular, the  outer  faces  slightly  impressed ;  composed  alternately  of  thin  and 
somewhat  thicker  plates,  the  latter  protruding  considerably  beyond  the 
others. 

Horhon  and  LocnlHff.  —  Upper  part  of  the  Hudson  River  group ;  Warren 
Co.,  0. ;  rare  at  Cinciniiati, 

Tjipc  specimen  formerly  in  the  collection  of  J.  Kelley  O'Neall,  now  in  the 
collection  of  Wachsmuth  and  Springer. 


\ 

i  i.  ' 

hiij 

I 

■ 

; 

i 

f: 

RKTEOCRIXID.E. 


181 


Rcmarh.  —  The  peculiarity  that  the  «iiialloMt  intcnndials  are  marginal 
and  lie  next  to  the  rudials  and  bawls,  instead  of  diininisliing  in  si/.e  upward, 
as  is  usually  the  case,  leads  to  the  conclusion  that  these  plates  were  intro- 
duced between  some  of  the  older  pieces,  and  are  secondary  plates  which 
cannot  be  homologized  with  the  primary  interradials  of  the  Actinocrinida>. 
The  structure  is  well  shown  in  our  ligure,  Plate  JX.  Fig.  1/,  which  represents 
the  inner  floor  of  a  fine  specimen  in  which  the  arrangement  of  tiie  primary 
interradials  is  very  little  disturbed,  being  1,  2,  .3,  all  of  them  isolated  and 
surrounded  by  small  supplementary  pieces.  We  shall  di.>icuss  this  subject 
further  in  our  remarks  upon  Xinocnints  jiciiwi//iis  and  A',  liiuri. 

We  have  had  no  opportunity  to  examine  the  type  ,<[)ecimen  of  Gh/ptncriiws 
mguatm  S.  A.  Miller,  in  the  collection  of  Dr.  R.  M.  Byrnes  of  Cincinnati,  but 
from  the  description  and  the  figure  we  are  strongly  inclined  to  regard  it  as 
a  large  specimen  of  liclcocviims  Oiiailli,  and  not  a  variety  of  that  species,  as 
suggested  by  Miller. 


? 


Beteocrinus  magnificus  (Miller). 
Plafe  IX.,  Fiff.  2. 

1SS3.     Gfiurom'iiiia  tnagnijieua  —  S.  A.  Miller;  Journ.  Ciiiciii.  Soc,  Nnt.  Hist.,  Vol.  V[.,  p.  2liO,  Plate  11, 

FiR.  2. 
1S''5.     Reteocriiiiis  mngiiijtrus  —  W.  ntul  Sr. ;  Revision  Palipocr.,  I'lirt  III.,  p.  91. 
ISSl).     Gaiirocriima  iiiat/niJii-Hn  —  S.  A.  Miller;  North  Amcr.  Gcol.  niid  riiliiunt.,  p.  217. 

A  larger  species  than  Rdcocriims  OncalU.  Calyx  subovoid  ;  section  pen- 
tangular; the  interradial  and  interdistichal  spaces  deeply  depressed;  the 
radial  ridges  broad,  flattened  at  their  upper  faces,  and  branching  from  the 
middle  of  the  radials  to  adjoining  basals. 

Infrabasals  small,  almost  covered  by  the  column.  Basals  of  medium  size, 
somewhat  convex,  their  upper  ends  inflected  toward  the  impressed  inter- 
radial areas,  the  interbasal  suture  lines  deeply  grooved,  and  forming  with 
the  lower  end  of  the  radials  a  lozo'igo-shaped  concavity.  Radijils  a  little 
narrower  at  the  top  than  at  the  boi  oi";  Costals  two,  narrow,  as  long  as  the 
radials,  and  without  lateral  extensions.  Distichals  very  variable  in  number, 
from  two  to  fifteen,  the  three  or  four  lower  ones  almost  as  large  as  the 
costals.  When  there  are  but  two  distichals,  which  is  apparently  exceptional, 
there  is  an  additional  bifurcation  in  the  calyx ;  while  in  the  other  cases  there 
is  only  one  more  bifurcation,  which  takes  place  in  the  free  arms,  and  the 
second  distichals  support  a  very  large  pinnule.     Arms  stout,  rounded  and 


]V 


!     1 


182 


THE  CKINOIDEA  CAMEUATA  OF  NOltTII   AMKllICA. 


coiistnicted  of  extremely  slioit,  Hlightly  convex, cimento  pieces.  Pinnule» 
composed  of  live  or  more  joints ;  long,  slender,  and  not  in  liiterul  contact. 
The  first  pinnule  is  borne  upon  tlie  second  distichnl,  iibove  which  every 
joint,  the  nxilinries  excepted,  is  pinnule-benring.  Interradiiil  luciis  more 
substantial  than  in  the  preceding  species,  the  plates  stouter,  and  the  median 
portions  rather  convex  than  concave.  Each  area  contains  from  twenty-five 
to  thirty  pieces,  some  larger  than  others,  of  all  possible  shapes,  and  indis- 
criminately arranged.  The  construction  of  the  anal  side  is  not  known.  The 
interdistichal  areas  apparently  extend  to  the  top  of  the  fifth  distichals,  are 
comparatively  flat,  and  compo.sed  of  similar  pieces  to  those  of  the  intcrradial 
spaces.  Construction  of  disk  and  anus  unknown.  Column  near  the  calyx 
distinctly  pentangular ;  the  nodal  joints  longer,  slightly  projecting  and 
rounded  at  the  margin ;  the  internodal  ones  shorter,  and  provided  with 
sharp  edges. 

ILn-lziin  ami  Locality.  —  Hudson  River  group,  Warren  Co.,  Ohio. 

The  tiipc  specimen  now  in  the  collection  of  Wachsmuth  and  Springer. 


XBNOCRINUS  S.  A.  iriLLEH. 

1881.  S.  A.  Miller;  Journ.  Ciiicin.  Soc.  Nnt.  Hist.,  Vol.  IV.,  p.  72. 

1881.  W.  and  Sp.  ;  Uovisiou  I'nliroer.,  rnri  II.,  p.  184. 

1883.  W.  and  Sp.  ;  Anicr.  Journ.  Sci.,  Vol.  XXV.,  p.  260. 

1884.  r.  II.  Caiipkxteb  j  I'liilos.  Trans.  Hoyal  Soc,  Part  III.,  p.  930. 
18S5.  W.  and  Sp. ;  Kcvision  Talffiocr.,  Part  III.,  )i.  94. 

1885.  W.  and  Sp. ;  Proceed.  Acad.  Kat.  Sci.  Pliila.,  p.  317. 
1889.  8.  A.  MiLLEii;  North  Ainer.  Gcol.  and  Pnkont.,  p.  287. 

Xcmcrinm  resembles  Rdeocrinvs,  but  is  without  infrabasals.  Bofals  four, 
forming  a  low  cup,  which  is  decagonal  at  the  upper  end ;  five  of  its  sides 
supporting  the  five  radials,  the  five  others  the  interradial  and  anal  plates. 
This  arrangement  gives  to  the  basals,  owing  to  their  abnormal  number,  a 
very  irregidar  form,  no  two  of  the  plates  being  alike. 
Radials  generally  a  little  larger  than  the  costals.  Costals 
two,  the  sides  bending  abruptly  inward  and  forming  highly 
elevated  ridges ;  the  distichals  to  about  the  fiflh  or  eighth 
plate  form  part  of  the  calyx.  The  lower  of  the.se  plates 
are  larger,  and  more  or  less  resenjble  the  costals,  while  the 
upper  ones  are  more  like  free  arm  plates.  Arms  ten, 
simple,  rather  stout;  composed  of  very  short  cuneiform 
pieces,  which  at  the  tips  of  the  arms  slightly  interlock. 


I'IG.   7. 


' 


p 


RKTEOCRINID^E. 


183 


, 


Interradial  npacos  deeply  iinpresHecl ;  composed  of  numcroim  iiiiniito 
pieces  without  definite  nnungenient ;  they  rest  upon  the  baoal.s,  Mepiimting 
the  rays  from  tiieir  bases  up.  Anal  interradius  wider  tliim  tlie  four  others; 
divided  longitudinally  by  a  row  of  folded  plates,  which  like  the  radials  have 
a  prominent  ridge  upon  the  outer  surface,  and  a  groove  at  the  inner  lloor. 
The  ridge  ends  in  a  small  protuberance  containing  the  anal  opening,  which 
points  upwards.  Interdistichal  spaces  also  deeply  depressed,  and  filled  by 
irregular,  minute  plates,  which  like  those  between  the  main  rays  pass  imper- 
ceptibly into  the  disk.  Ventral  disk  comparatively  flat,  composed  through- 
out of  very  small  pieces ;  orals  being  unrepresented,  and  the  disk  ambulacra 
subtegminal. 

Column  quadrangular,  with  pentangular  central  canal,  the  angles  of 
which  are  directed  interradially, 

D'lsl ribiitlon.  —  Tiiis  genus,  so  far  as  known,  is  limited  to  the  upper  part 
of  tlie  Hudson  River  group  of  Ohio. 

Type.  —  Xcnocrinus  jieiiicilliis  Miller. 

licmarh.  —  We  place  i.i  this  genus  Gli/ptocrimis  Daeri  Meek,  which,  ns  we 
have  discovered,  has  a  quadrangular  stem  and  four  basals.  Xmocrinua  is  the 
only  monocyclic  genus  in  which  interradials  come  in  contact  with  the  basals 
at  all  sides,  but  we  doubt  if  its  interradials  separated  the  rays  as  completely 
as  in  the  case  of  the  Rhodocrinidoo.  In  a  specimen  of  X.  Bacri  from  the 
collection  of  Mr,  I.  II.  Harris  (Plato  IX.  Fig.  5c),  in  which  portions  of  the 
inner  floor  are  exposed,  it  is  plainly  seen  that  the  lower  ends  of  adjoining 
radials  touch  each  other,  and  after  a  careful  study  of  the  structure  we  are 
inclined  to  believe  that  the  small  accessory  pieces,  which  seem  to  separate 
the  radials,  rest  upon  the  lower  outer  margins  of  the  plates,  and  not  between 
the  plates. 

Xenoorinus  penioillus  ^[illkr. 
Plate  IX.  Figs.  Ga,  b. 

19S1.    S.  A.  Miller;  Journ.  Cinciii.  Soc.  Nat.  Hist,  Vol.  IV.,  p.  72,  Pinto  1,  Fig.  3j  nnd  ibid.,  p.  170, 

riiite  t,  Fig.  6. 
1SS3.    W.  and  Sr. ;  Amor.  Joiim.  of  Sci.,  Vol.  XXV.,  p.  200,  nnd  1S83,  Kcviaioa  Pnlffiocr.  Part  III., 

p.  90. 

A  small  species.  Calyx  elongate,  once  and  a  half  as  high  as  wide,  ob- 
conical  at  the  lower  end,  then  rising  almost  vertically  to  the  free  arms ;  the 
radials  and  brachials  highly  elevated,  folded  lengthwise  with  rounded  back ; 
the  interradial  spaces  deeply  impressed,  the  plates  somewhat  nodose. 


1? 


184 


TlIK  CUIXOIDKA    CAMKHATA  OK   NOUTU   AMKURA. 


Diisiils  ioriiiiii}^  11  siiijill  hii.siii,  wliicli  iit  tliu  Ituttuiii  irt  Migtilly  i>.\ciiV(iti:'<1 
for  thu  i'fC('[itioii  (»r  tliu  culuiiui.  UmliulM  iiiid  cu.^tiiln  ol'  iioiuly  ciiiiiil  nI/.u, 
<ino  tliinl  l()iij,'i'r  tliiiii  wido,  tlieir  liitonil  I'licu!*  (lisliiictly  coiivux,  ho  as  to  j;ivt' 
to  tlio  hIiIch  a  sort  of  t^ciillopcil  uppoiinuicu.  DiHliclmU  freu  from  tlic  iiiiitli 
or  tenth  pliitu;  lliu  four  or  livu  lower  ouum  uloiigiilu,  in  I'onn  iiiiil  hI/m  ru- 
Honiljl'mj,'  llio  fostiils ;  tin-  Miicct'cdinj;  oni'M  graclmilly  decreusing  in  longtli; 
iiml  tlio  iippiT  Olios  us  short  as  the  IVuo  arm  phiti's.  Anns  ten,  appiireiiily 
short;  coiii[)i)SL'd  of  low  ciinoato  pieces  with  somewhat  ronndod  outer  e<lges. 
Tlio  (irst  pinmilo  starts  from  the  second  distichal ;  it  is  stronger  than  the 
others,  and,  liiio  the  throe  or  lour  succeeding  ones,  incorporated  into  the 
calyx.  The  free  pinnules  are  more  slender  and  longer ;  they  consist  of  six 
to  seven  joints,  twice  as  long  as  wido.  Interradial  spaces  deepening  toward 
the  middle,  and  deepest  in  their  upper  portions.  They  are  composed  of 
a  very  largo  numher  of  miiuito  pieces,  are  irroguhirly  arranged,  tuberculous 
and  slightly  stellate.  Similar  plates  till  up  the  spaces  between  the  disticlials. 
Anal  interradiiis  wider;  divided  by  a  longitudinal  row  of  llfteon  or  more 
largo  anal  plates,  whiiih  in  form  and  size  resemble  the  lower  brachials,  and 
their  sides  are  .scalloped  in  a  similar  manner.  The  row  termiiiiites  in  a  small 
protuberance  near  the  margin  of  the  disk,  which  contains  the  anal  opening. 
Ventral  disk  hemispherical,  pentangular  in  outline,  the  surface  slightly  ele- 
vated in  the  direction  of  the  food  grooves;  compo.sed  of  hundreds  of  minute 
pieces ;  the  ambulacra  subtegminal.  Column  quadrangular,  its  sides  dis- 
tinctly concave.     Axial  canal  pentangular. 

IlorLon  tinil  Loca/i///.  —  Hudson  River  group ;  Warren  Co.,  0. 

T///ICIS  in  the  collection  of  Mr.  I.  II.  Harris  of  Waynesville,  O. 

licmurhs.  —  Among  the  specimens  examined,  there  is  a  very  interesting 
small  Olio,  in  which  the  interradials  do  not  touch  the  basals.  In  this  speci- 
men it  is  most  romarkablo  how  the  interradials  vary  in  size.  Three  of  them 
are  tolerably  large,  but  they  are  isolated  from  each  other,  and  from  the 
radials  and  basals,  by  numerous  small,  almost  microscopic  pieces,  smaller 
than  the  corresponding  plates  in  more  mature  specimens.  The  larger  plates 
occupy  approximately  the  position  of  the  first  and  second  row  of  inter- 
brachials  in  the  ActinocrinidaD,  and  undoubtedly  represent  them,  being 
pushed  out  of  position  by  the  development  and  intercalation  of  supidemen- 
tary  pieces. 


Hi 


RKTK()C'niNIIl-K. 


186 


XenoorlDui  Baeri  (Mkk.k). 
I'lah  IX.  Fiijx.  6ii-il. 

187*.  Olyp/'HriuHi  Ihifri  —  Mhtiii  Ainrr.  .Inurii,  ^<l■i  ,  Vul    III.  (Hi!  »cr.),  p.  2(10. 

l><7;i.  Ill,1lilni-riii«»  lt,(,;-i  —  Mkkk;  (i((il    l(r|i.  OIiIm,  I'liliruiil.,  Vol.  I.,  |i,  ;)7,  I'lalc  i.  Ki({.  1. 

INSO,  llli/iilw,-inH>  l,ii,;i  —  .S.  A.  .Mll.l.KHi  Jciiirii.  Ciiioia   Siv    Nul    lli^l..  V.jI.  III.,  I'liiti'  7,  Fig.  t. 

ISSl.  H'/>f,,-nHMt  llihi-i—  \V.  iiimI  Mi-.  ;   l(i'n>luii  I'mIiimut,,  I'ihI  II.,  |>   IICI. 

|s»;»,  H'li'fH-riHun  limn  —  \V.  ami  Sf, ;  Aiiicr  .Icpiini.  Sii,  Vol.  XXV  ,  |i  im. 

l^S:i.  li/y/j/>ir,-i,iHt/„i';-i—!*.  A.  .Mll.l.Mt;  Jnuni.  Cliiiih.  Scic.  Nal.  Iliil,,  Vul.  IV.,  p,  ij^ii. 

1SS3.  .\';wn„u.i  Hi„;i  —  \V.  and  Si'.  ;   ItcvUioii  I'alaiMr  ,  Tail   III,,  |i   IMl 

1.S81I.  Xfiiiifi-iiiu^  /iiiiui  —  S.  A.  Mii.i.Kii;   Ni)rtli  Aiiicr.  (Ji'iilug^  ami  ruln'mil.,  |>.  itS. 

Dorsal  oii|)  iiiglior  llmii  widu ;  Hu))uvui(l ;  dupreH.scd  at  tliu  iiiterriulial 
Mpnci'M,  Imt  not  ho  imicli  no  as  in  X.piniciUux;  cvohh-hwX'mw  pt'Mlanjfiilar. 

lia.'^ulH  Hiiiall,  only  tliuir  iippor  aiigloM  visiblu  in  a  h'uIo  view.  KadiaU  and 
coMtals  elongati'.  Ibrined  into  conspicuous  rounded  riilgcs,  wliicii  occupy 
almost  tlio  entire  widtli  of  tlie  plates.  Disticlials  free  from  tiie  lil'lh  or  si.\tli 
jtlato  ;  the  two  proximal  ones  as  large  as  the  costals,  the  third  somewhat 
shorter,  and  tlie  upper  one.s  but  little  longer  than  the  free  plates.  Arms 
ten,  simple,  long,  rather  Htout;  composed  of  very  siiort,  transverse  joints, 
with  slightly  convex  outer  faces.  The  lower  arm  joints  rectangidar,  followed 
by  cimcate  pieces,  which  slightly  interlock.  Interradial  areas  dee|)est  iu  the 
middle;  composed  of  numerous  very  small,  convex  pieces,  with  a  somewhat 
corrugated  surface.  Anal  side  dividctl  by  a  longi  i;dinal  row  of  anal  plates, 
shaped  like  the  radials  and  costals.  Ventral  disk  low-hemispherical ;  plates 
very  minute;  the  po.sition  of  tho  anus  uidtnown.  Column  quadrangular, 
with  obtuse  angles;  the  joints  extentled  outward  into  hmg  knife-like  edges. 

Ilorl.viiii  ioiil  LncaUl;/.  —  Hudson  River  group  ;  Warren  Co,.  0.,  and  Uich- 
mond,  Ind. 

Tiu'  specimens  figured  are  from  the  Collection  of  Wachsnuith  and 
Springer,  and  that  of  I,  H.  Harris,  Esq.,  of  Waynesville,  0. 


? 


TANAOCRINUa  (n-v.  gen.),  W.  and  Sp. 
(Tdiiid?.  slt'iidpr;  KpiVoi'.  a  lily). 

Resembling  IMcocfinvs,  but  without  Infrabasals,  and  the  radials  in  laterjvl 
contact  except  at  anal  side.  Symmetry  decidedly  bilateral.  Arms  long  and 
slender. 

Basals  small ;  the  posterior  one  truncated  at  the  upper  end,  and  followed 
by  a  large  anal  plate.     Costals  two,  narrower  than  the  radials,  and  folded 


186 


THE  CRIXOIDEA  CAMERATA  OF  NORTH  AMERICA. 


ll 


■  I. 

■  1 


:  I 


•1  I 


like  arm  plates.  Distichals  numerous,  for  the  most  pnrt  incorporated  into 
the  calyx.     Arms  branching  once  or  twice  beyond  the  calyx. 

Interradial  and  interdistichal  areas  deeply  depressed,  filled  by  numerous 
minute,  irregular  pieces.  Anal  side  wider  than  the  other  four,  divided  by 
a  median  longitudinal  row  of  large  anal  plates,  folded  like  the  costals. 
Structure  of  the  disk  and  position  of  the  anus  unknown.  Column  round 
or  obscurely  pentagonal. 

Distribution,  etc.  —  Restricted  to  the  Hudson  River  group  of  America. 

T//2}e  of  the  genus :  —  Tanaocrinus  typus  W.  and  Sp, 

Tanaoorinus  typus  (nov.  spec),  W.  and  Sp. 
Plaie  IX.  Fi(js  7a,  b,  c. 

A  small  and  slender  .species.  Calyx  elongate;  broadly  truncate  at  the 
lower  end  ;  plates  without  ornamentation. 

Basals  five,  plainly  visible  in  a  side  view  ;  forming  a  short  cup,  which  is 
slightly  excavated  at  the  bottom.  The  upper  laces  in  four  of  the  plates  sharply 
angular,  that  of  the  posterior  side  narrowly  truncate.  Radials  the  largest 
plates  of  the  calyx,  much  narrower  at  the  top  than  at  the  bottom,  rounded 
at  the  lower  face.  They  are  connected  laterally,  forming  a  wide  and  deep 
notch  for  the  reception  of  the  interradials,  except  at  the  anal  side  where  the 
first  anal  plate  rests  directly  upon  the  basals.  Costals  two,  as  long  as  the 
radials  but  narrower;  folded  and  elevated  in  the  middle,  the  lateral  margins 
on  a  level  with  the  interradials.  Distichals  seven  to  eight;  all,  or  nearly 
all  of  them,  incorporated  into  the  calyx ;  the  lower  ones  as  long  as  the  costals, 
but  a  little  narrower;  the  upper  ones  gradually  growing  .shorter,  and  taking 
the  form  of  free  arm  joints.  Palmars  twelve  or  more,  all  of  them  free.  The 
arms  branch  two  or  three  times ;  they  are  long,  cylindrical,  and  taper  gradu- 
ally to  the  tips,  where  they  become  very  delicate  and  thread-like.  They  are 
composed  of  short,  cuneate  pieces  which  do  not  interlock.  The  first  pinnule 
is  given  off  from  tlie  second  distichal ;  it  is  more  than  twice  as  large  as  any 
of  the  others,  and  it,  as  well  as  the  three  or  four  succeeding  ones,  is  enclosed 
in  the  calyx.  Interradial  and  interdistichal  spaces  deeply  depressed,  the 
plates  very  small  and  without  definite  arrangement.  Anal  side  twice  as  wide 
as  the  other  four,  and  divided  longitudinally  by  an  anal  ridge  of  five  to  six 
large  plates,  which  closely  resemble  the  radials  and  costals.  The  first  anal 
plate,  which  rests  upon  the  basals,  is  nearly  as  large  as  the  radials,  and  like 


I  " 


RETEOCRINID^E. 


187 


them  narrower  above  than  below ;  the  succeeding  ones  are  a  little  smaller 
than  the  costals.  Ventral  disk  not  visible  in  the  specimens.  Column  com- 
paratively large  and  obscurely  pentagonal,  the  nodal  joints  larger,  and  with 
slightly  undulating  edges. 

Horizon  and  LocaUty.  —  Upper  part  of  the  Hudson  River  group,  Warren 

Co.,  0. 

The  type  specimens,  which  are  in  our  collection,  were  presented  to  us  by 

Dr.  S.  S.  Scoville  of  Lebanon. 


h 


r 


n 


I  -   -r 


4  I 


■■■"."I  '-5!^" 


THYSANOCRINID^  W.  and  Sp. 

(GLYPTASTERIDJi:  W.  and  Sp.  1885). 

DiCYCLic.     Lower  brachials  and  interbrachials  forming  an  important  part  of 
THE  dorsal  cup  ;   interbrachials  well  defined.     Radials  in  contact  except 

AT  the  posterior  SIDE,    WHERE   THEY  ARE   SEPARATED   BY   AN   ANAL   PLATE. 

Anuli/sis  of  the  Genera. 
Infrabasals  5.. 

A.    Anal  side  slioiitly  elevated.    Asvs  without  a  tube. 

1.  First  anal  plute  followed  hij  three  plates. 

a.  Dorsal  cup  deep. 

Arms  uniseiial,  10 Pttchocrinus. 

Arms  biserial,  erect,  ten  to  twenty Thysanocrinus. 

b.  Dorsal  cup  short,  almost  flat. 

Arms  pendent,  posterior  oral  and  radial  dome  plates 

spiniferous Hyptiocrinus. 

2.  All  interbrachiul  spaces  liavlng  a  single  large  plate       ....  Idiocbinus. 
■"B.    Anal  side  BULfii.vo.    Axus  at  the  end  of  a  tube, 

1.  First  anal  plate  followed  by  three  small  plates. 

Rays  prodnced  into  tubular  extensions. 

Infrabasals  large Lampteeocrinus. 

2.  First  anal  plate  followed  by  three  large  pilates. 

Rays  branching  in  the  regular  way. 

Infrabasals  small Siphonocrinus, 


Geological  and  Geographical  Distribution. 
Number  of  known  species, 

(Open  figures  indicate  American,  those  marlved  (  ),  European.) 


Formation. 

TlITSANOCRIXin.t. 

General. 

American. 

Approximate 

Kuropean 
Equivalents. 

3 

c: 

P.4 

CO 

cn 

1 

3 

.2 

2 
s 

o 

1 

< 

p 

/  Upper 
( Lower 

Niagara. 

Dudley 
Gotland. 

5(7) 

1 

4 

1 

3 

Huds.  River, 

2          i 

1 

Total  species    ...    23 

2 

5(7) 

4 

1 

3 

Itil 


THYSANOCRIXIDiE. 


18D 


Remarks.  —  "We  have  clianged  the  name  Glyptasteiidfe,  whieli  we  pro- 
posed in  1885,*  into  Thysiuiocrinidre,  because  we  found  it  necessary  to  give 
up  Hall's  genus  Gli/pUtdcr.  We  also  discard  Dwicmcnnus  Phillips,  and  Fn- 
crinus  Angelin,  and  arrange  the  species  of  both  luider  T/i'/miiominis-.i  That 
Phillips'  figures  oi  Dinwoenims  were  insufficient  for  generic  identification,  is 
shown  by  the  fact  that  the  genus  has  been  referred  by  Koeiner  and  Dujardin 


o 

Fir.  8.     T/iymnocriiiiis. 


Q- 


9j 


^  "S^  f^ 

Fifi.  9.     LiiinplfrorriDiix. 


and  Hupe  to  the  Cyathocrinido9,  while  Zittel  'made  it  the  type  of  a  mono- 
cyclic family.  Glypiaster  and  Eiwrimis  were  placed  by  Zittel  along  with 
Lamptcrocrinm,  Archwocrmm,  and  Gli/piocrinns  under  the  Glyptocrinidaj ;  in 
which  he  was  followed  by  S.  A.  Miller,  who  added  Rctcocrimis  and  Xaiocrimis, 
but  withdrew  them  again  in  1889.  Tlii/smwcrhms  was  placed  at  first  by  both 
authors  under  the  Ilhodocrinidaj,  from  which  afterwards  Miller  removed  it  to 
the  Glyptasteridte. 

The  Thysanocrinidie  have  their  closest  affinities  with  the  Ehodocrinidaj. 
Both  are  dicyclic,  but  in  the  RhodocrinidiB  the  interradials  at  all  five  sides 
are  in  contact  with  the  basals,  thus,  as  a  general  rule,  completely  isolating 
the  radials  laterally ;  while  in  the  Thysanocrinidre  the  radials  are  in  contact 
all  around  except  at  the  posterior  side,  where  the  anal  plate  overlies  the 
basals.  This  bilateral  symmetry  in  the  arrangement  of  the  plates  of  the 
dorsal  cup  is  accompanied  by  a  marked  asymmetry  in  the  general  form  of 
the  calyx,  and  especially  of  the  ventral  disk,  which  is  more  or  less  enlarged 


^ 


111 


*  Revision,  Part  III.,  p.  89. 


t  See  Hiulcr  Tlii/saiwi-riinis. 


190 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


posteriorly  in  most  of  the  species  of  tlie  Thysanocrinidoe.  In  the  new  genus 
Idioci'imts,  in  which  there  is  but  one  interbrachial  plate  to  each  of  the  five 
sides,  there  is  no  special  anal  plate,  and  the  posterior  interradial,  which  is 
larger  and  rests  upon  the  basals,  serves  as  the  anal. 

The  family  is  confined  to  the  Silurian,  and  is  composed  of  six  genera, 
with  twenty-three  species,  of  which  sixteen  are  from  America,  and  seven 
from  the  upper  Silurian  of  England  and  Sweden. 


1830. 
1S41. 
1850. 
1852. 
1852. 
185-2. 
1855. 
1857. 

185.9. 

1802. 

1S63. 
1873. 
1878. 
1S7S. 

1879. 


18S1. 


1889. 


THTSANOCRINUS  Hall. 

Dimerocrinm  —  Phillips;  Murcliisoii's  Silur.  Syst.,  p.  074,  Plate  17,  Figs.  4  and  5. 

IHmerocrinus  —  .MCi.lkr;  Monatshcr.  Berlin.  Akad.  d.  Wisseiiscli.,  p.  208. 

Uimerocrhius  —  d'Ouhigny  ;  Prodrome  I.,  p.  40. 

Glt/ptaster  —  Wxhi,;  Paliroiit.  N.  York,  Vol.  XL,  p.  187. 

Thymmcrinus — Hall;  Ibid.  p.  190. 

Dimerocrinus —  u'OnniGNY  ;  Cours  I'lenicnt.,  Part  11.,  p.  142. 

Dimerocrimis  —  Hokmeb;  Lelluca  Geognost.  (Ausg.  3),  p.  237. 

(  Thysa„oerii,H.'<  \  _  ^^^^^^  .  ^^^^^^  j^  Paleont.,  Vol.  IV.,  pp.  317  wid  318,  Plate  C,  Tig.  13. 

(  DiiiierorriiiHS   ) 
JJimerorriiius  —  lklvncimoii ;  Siliirla  (3d  cd.),  p.  535,  Plate  13,  Figs.  4  and  5. 

(  Thymnacnnm  )  _Di,j4iin,N  and  IIupk;  Hist.  Natnr.  des  Zoophytes,  pp.  128  and  131. 

I  himerocniiHs   ) 

Qlyptanter  —  WKU.;  Trans.  Albany  Inst.,  Vol.  IV.,  p.  202. 
D'merocnuus  —  'SsK\.xw.\  Catnl.  Oeol.  Mnscnm,  Cambridge,  p.  120. 
Glyptaster  —  WkiA.;  28tli  Hep.  N.  Y.  Stale  Mus.  Nat.  Hist.  (ed.  2),  pp.  131  and  133. 
Eiicriiiiis  —  Angklin;  Iconogr.  Criii  Sueciie,  p.  24. 

/  Thymnocrinm  \ 

\  —  Zitiel  ;  Handb.  d.  Palxont.,  Vol.  I.,  pp.  368  and  375. 

-W.  and  Sp.;   Revision  Palieocr.,  Part  H.,  pp.  193  to  199.    Also  ibid.,  Part 
III.,  p.  101. 


Glyiiliister 

Dimerocrinus 
.  Eiicriiiiia 
'  Glyf  taster 

Dimerocriniin 
I  E/ii-riiiiis 
•■  Thymnocrmus  (syii.  of  Dimerocrinus). 


(.  Glyptaster 
<  Eiicriims 
'  Tliysanocr 


[■  —  S.  A. 
fill  us  ) 


MiLLEK ;  N.  Am.  Geol.  and  Palffiontology. 


Syn.    Dimerocrinus  Phillips. 
Syn.     Glyptaster  Hall. 
Syn.     Eucrinus  Angelin. 


Calyx  subglobose,  urn  or  bell-shaped  ;  the  rays  marked  by  a  more  or  less 
conspicuous  ridge;  the  general  surface  of  the  plates  smooth  or  variously 
ornamented.  Tnfrabasals  five,  small,  barely  protruding  beyond  the  column, 
or  entirely  hidden  by  it.  Basals  five,  four  of  them  equal,  angular  alcove  ;  the 
fifth  truncated,  and  supporting  a  large  anal  plate.  Eadials  considerably 
larger  than  the  costals,  their  lower  sides  distinctly  angular,  the  lateral  faces 
comparatively  short.     Costals  two.     Arms  ten  or  twenty,  rather  strong  and 


, 


■!:iv  i 


THYSANOCRINID.E. 


191 


biserial  ;  pinnules  long.  The  first  interbracliial  large,  resting  upon  the 
sloping  upper  corners  of  two  radials  and  against  the  costals.  There  are  two 
plates  in  the  second  range,  and  often  smaller  ones  above,  which  connect  with 
the  plates  of  the  disk.  The  anal  side  considerably  wider;  the  first  plate 
large,  hexagonal,  resting  upon  the  posterior  basal ;  the  s-econd  range  contain- 
ing three  plates.  Some  species  have  an  uninterrupted  row  of  anal  plates  all 
the  way  to  the  anal  opening.  Interdistichals  generally  represented  and  rather 
large.  Structure  of  the  ventral  disk  and  position  of  the  anus  only  known 
in  one  species.  (See  Thysanocrimis  inornaUts)  column  round  or  obtusely 
pentangular. 

Distribution.  —  Restricted  to  the  Niagara  group  of  America,  the  Wenlock 
group  of  England,  and  its  equivalent  in  Sweden. 

Type  of  the  genus.  —  Thysumcrimis  liliiformis  Hall. 

Remarks.  —  We  have  reduced  Dimcrocrinus,  Ghjptaster,  TInjsanocrimis 
and  Eucriims  to  one  genus,  finding  it  utterly  impossible  to  distingui.sh  them 
generically.  There  is  some  doubt,  however,  by  what  name  the  genus  should 
be  known.  The  name  Diwerocrinus  was  applied  by  Phillips  to  two  species 
from  Dudley,  D.  decadcwtylns  and  D.  icosidactylus.  Both  wore  figured  but 
not  described,  and  the  figures  were  poor  and  did  not  reveal  the  character- 
istics of  the  geinis.  A  meagre  description  was  given  by  Miiller,  who  men- 
tioned "  a  pelvis,"  succeeded  by  3  X  5  radials,  and  two  series  of  arm  plates. 
D'Orbigny  described  it  with  three  basals,  succeeded  by  three  rings  of  plates. 
From  such  vague  and  incorrect  descriptions,  Hall  could  not  suspect  that 
a  species  with  five  ba.sals  and  infrabasals  would  be  generically  identical  with 
species  described  as  possessing  three  basals  and  no  infraba.«als,  and  we  believe 
he  was  justified  in  proposing  for  his  species  a  new  genus.  Pictet  and 
Dujardin  and  Hup^,  who  accepted  both  genera,  placed  them  near  together. 
Zittel,  however,  even  refers  them  to  distinct  families.  We  were  the  first  to 
point  out  the  generic  identity  of  Thysanocrimis  with  the  forms  which  are 
held  to  represent  Dimcrocrinus  dccadactylus  and  D.  icosidactylus,  but  di.s- 
criminatcd  in  favor  of  the  older  name  Dimcrocrinvs,  which  we  now  think 
was  scarcely  fair  to  Hall.  Besides,  we  accepted  Glyptastcr  and  Encrimts, 
though  with  some  hesitation,  making  the  latter  a  subgenus  of  the  former. 
The  name  Glyptastcr  was  proposed  for  a  solitary  specimen,  described  ns 
6.  hrachiatus,  in  which  all  the  plates  of  the  calyx  were  obscured  by  matrix, 
but  showing  ten  spreading  biserial  arms  without  visible  pinnules,  and  it 
was  principally  upon  the  absence  of  pinnules,  it  seems,  that  the  genus  was 


? 


-- 1 


/I 


102 


THE  CRINOIDEA  CAMERATA  OF   NORTH  AMERICA. 


founded.  Through  the  kindness  of  Prof.  Whitfield  we  were  permitted  to 
examine  this  specimen,  and  to  free  it  from  the  surrounding  matrix,  when  we 
found  tiie  pinnulco  well  developed,  and  the  plates  of  the  calyx  arranged  as 
in  the  typical  form  of  Thijsanocrimis  (Plate  XVIII.  Fig.  4). 

Eucrinus  was  separated  from  Tlnjmnocrinus  on  account  of  having  twenty 
arms,  as  against  ten  in  the  latter.  A  bifurcation  or  two,  more  or  less,  cannot 
be  regarded  as  a  good  generic  distinction,  and  we  therefore  place  Angolin's 
species :  Eucrinus  iHfemHllulls,  E.  Imvls,  E.  ormifus,  E.  qmnqitamjularis  and 
E.  sjjeciosns, under  Thysanocrinus ;  but  not  his  E.  minor  or  E.  venustus,  which 
are  types  of  a  different  genus.  Rhodocrimis  quinquehhus  Schultze,  which  we 
formerly  placed  under  Eucrinus,  is  a  Rliodocrinoid.  Thysanociinm  {lihodo- 
crinus)  viicrvhasilis,  and  7'h.  (R/iodocrinus)  pyriformis  Billings,  have  been  re- 
ferred by  us  to  Archavcrinus ;  Th.  immaturus  to  Idiocrinus.  TTiysanocrimis 
wnhatus  and  Th.  cunalictdutus  are  named  from  arm  fragments.  Dimerocrinus 
oliijoptilis,  and  its  synonym  D.  cqMis  from  Russia,  belong  to  Taxocrinus. 
Gli/ptaster  penUoHjuluris  Hall  is  described  from  internal  casts,  and  is,  to  say 
the  least,  a  doubtful  species.  Cijathocrinus  ivcddroncnsis  S.  A.  Miller  {Dimcro- 
rrlnns  icaldroncusis  W.  and  Sp.)  cannot  be  identified  from  the  description  and 
liguie,  but  may  be  a  young  Tlajsaiwcrinus  inoniatus.  Neither  can  Ghjptaskr 
E(jani  S.  A.  Miller,  which  is  described  from  a  fragmentary  specimen. 


Thysanocrinus  liliiformiB  Hall. 
Plate  XVIII.  Fig.  4- 

1S52.     nymnorriiius  li/ii/oniiis  —  ll\LL;  Pnhtoiit.  N.  York,  Vol.  II.,  p.  1S8,  Figs.  Iff-/. 

1S81.     Dimcroniiiiis  li/iijbmis—W.  mid  Sp.  ;  Revision  I'uliuocr.,  Pint  II.,  p.  199,  and  Proceed.  Acad.  Nat. 

Sci.  Phila.,  p.  373. 
18S9.     ni/sciiioeriiiHs  lilii/oruiis  —  S.  A.  Miller;  N.  Amcr.  Geol.  and  Palrcout.,  p.  2S6. 

Form  of  calyx  apparently  globose  (the  exact  shape  cannot  be  ascertained 
owing  to  the  somewhat  crushed  condition  of  the  type  specimen) ;  the  plates 
ornamented  by  elongate  nodes  or  interrupted  stritc,  which  give  to  the  surface 
a  corrugated  appearance. 

Infrabasals  small,  scarcely  visible  in  a  side  view.  Basals  nearly  as  large 
as  the  radials;  that  of  the  anal  side  oven  larger  and  broadly  truncate,  the 
others  angular  above.  All  plates  in  a  radial  direction  provided  with  a  low. 
almost  flat,  obscure  ridge,  following  the  median  line  of  the  plates,  and 
covered  by  longitudinal  strife  which  are  continued  into  the  arms.  Radials 
wider  than  long,  but  slightly  angular  below;  their  lateral  faces  short,  leaving 


X 


v.. 


TIIYSAX0CR1N1D7E. 


103 


a  deep  notch  for  the  reception  of  the  first  interbrachials.  Costnls  about  of 
equal  size,  considerably  snuiller  than  the  radials.  Arms  ten,  rather  stout,  the 
two  lower  plates, which  are  included  in  the  calyx, longer  than  the  free  plates; 
the  latter  short,  arranged  in  two  series,  with  a  few  cuneate  interlocking  joints 
at  the  proximal  end.  Pinnules  long,  closely  packed ;  composed  of  aliout  six 
remarkably  long  joints,  which  are  thickest  at  the  ends.  First  interbrachials 
as  large  as  the  radials ;  succeeded  by  two  much  smaller  plates,  and  a  few 
still  smaller  ones  above.  Anal  plate  large,  resting  upon  the  truncated  basal ; 
succeeded  by  three  plates  in  the  second  row.  Siructure  of  di.«k  and  posif-on 
of  aral  opening  unknown.  Column  round,  strong,  the  nodal  joints  wider  and 
longer,  rounded  at  their  edges. 

Iloruon  and  Locali/ij.  —  Niagara  group ;  Lockjjort,  N.  Y. 

Type  in  the  Museum  of  Cornell  University  at  Ithaca. 


X 


V 


Thysanocrinus  inornatus  (Ham.). 
Plate  XVIII.  FUjs.  6a,  h,  c,  d,  and  XIX.  Fig.  5. 

1863.     Olypittster  iTOm//«.t  — IIai.lj  Trniis.  Alb.  Inst.,  Vdl.  IV.,  p.  205;  nlsn  2Stli  Ecp.  N,  Y.  Sintn  Mns. 

Nat.  Hist.  (1S79,  Ed.  11.,  p.  \\V\\  I'lntc  It,  Figs.  1-G;  ulso  lltli  Itcj).  Gcol.  Surv.  liuliiinn, 

I8S1,  p.  203,  Plate  13,  Figs.  1-6. 
1881.     Gli/ptaster  imrnaliis  —  W.  mid  Sr. ;  Kcvision  ralttocr.,  Part  II.,  p.  196. 

Calyx  somewhat  urn-shaped,  the  sides  slightly  convex ;  cross-.section  at 
the  top  of  the  costals  pentagonal,  the  angles  corresponding  to  the  rnys ; 
across  the  disticlmls  decagonal. 

Infrabasals  very  minute,  only  the  extreme  points  of  the  plates  visible 
beyond  the  column.*  The  ornamentation  consists  of  single  series  of  broad, 
ill-defined  radiating  ridges  or  elevations.  Some  of  the  more  prominent  ones 
follow  the  median  line  of  the  rays;  while  others  take  a  lateral  direction, 
radiating  from  the  centre  of  the  plates  to  the  margins,  where  they  meet 
with  similar  ridges  from  the  interbrachials  and  basaks, 

Basals  large,  their  lower  margins  thickened  and  expanded  into  nodes  — 
one  to  each  plate  —  which  stand  on  a  level  with  the  top  stem  joint,  and 
form  a  marked  pentalobate  rim  around  it.  Eadials  larger  than  the  bnsals, 
and  wider  than  long.     First  costals  considerably  smaller  and  quadrangular, 

•  Prof.  Hall  described  tlie  "  basals  "  —  the  infrabasals  of  modern  terminology  —  as  "  nmeli  developed, 
distinetly  pcutanguliir,  «i(li  a  donble  or  triple  node  on  oarh  plate,  and  spreading  beyond  tlie  eolnnin."  From 
tliis  description  we  s\ispect  that  the  antlior  took  tbe  nodes  at  tlie  lower  end  of  the  hasah  for  plates,  and  over- 
looked the  small  iiifrnbasals  which  are  rarely  observed.  AVe  draw  attention  to  this,  breanse  Hall,  in  compar- 
ing this  species  with  bis  "  Glyptusler"  oceidentatis,  makes  "the  greater  dcvcloimient  of  the  basal  plates" 

a  specific  distinction. 

25 


!| 


I 


194 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


the  second  iibout  as  large  ns  the  firist.  DiHticImIs  four  in  the  calyx,  the  rows 
wpanited  by  from  one  to  three  intordLstichals.  The  second  distichal  bears 
a  pinnule,  wliicii  is  for  the  most  part  incorporated  into  the  calyx.  Arms 
uidtnown.  Interbrachial  spaces  deeply  depressed,  so  as  to  give  to  the  calyx 
at  the  arm  bases  a  decidedly  lobed  appearance ;  the  first  plate  nearly  as 
large  as  the  radials,  the  two  of  the  second  row  slightly  smaller,  followed  by 
much  smaller  ones  in  the  third  and  fourth  rows.  Anal  interradius  consider- 
ably wider,  more  depressed,  and  longitudinally  divided  by  a  row  of  elongate, 
hexagonal  anal  plates,  which  form  a  conspicuous,  rounded  ridge  reaching  to 
the  anal  opening.  The  plates  at  each  side  of  the  ridge  consist  of  about  the 
same  number,  and  are  arranged  in  a  similar  nuuiner  as  the  interbrachials  of 
the  fovU'  other  sides.  Anal  opening  subcentral,  in  the  middle  of  a  small  pro- 
jection. Ventral  disk  depressed.  Orals  pushed  to  the  anterior  side;  four  of 
them  much  smaller,  and  arranged  in  a  !<lightly  curving  row  around  the 
posterior  one,  which  rests  against  the  anal  protuberance.  Covering  jiicces 
of  the  ambulacra  exposed  at  the  surface;  they  consist  of  two  series  of  very 
short  transverse  pieces,  alternately  arranged,  forming  highly  elevated  ridges, 
Avhich  gradually  decrease  in  width  as  they  approach  the  arms.  Interambn- 
lacral  plates  continuous  with  the  interbrtichials ;  they  are  small,  irregular,  and 
form  deep  depressions  upon  the  surface,  which  contrast  strongly  with  the 
elevations  along  the  ambulacra.  Column  round ;  axial  canal  above  medium 
size ;  the  outer  edge  of  the  top  joint  beautifully  erenulated. 

Horizon  and  Localitij.  —  Niagara  group ;  Waldron  and  Hartsville,  Ind., 
and  Racine,  Wise. 

Types  in  the  American  Museum  of  Natural  History,  New  York. 


Thysanocrinus  oocidentalis  Hall. 
Plate  XVIII.  Fiqs.  5a,  h,  c. 


;  Trniis.  Alb.  Inst.,  Vol.  IV.,  p.  204  (Abstr.  p.  10);  nlso  28th  Bcp. 
Hist.  (cd.  2,),  1S70,  p.  V.Vi,  riiitu  13,  Figs.  7-11;  also  11th  Kcp. 


1863.     Gli/ptasfer  occideiitalis  —  Hail;  Trniis.  Alb.  Inst 

N.  York  State  Mus.  Kiit 

Gcol.  Surv.  Indiana,  1S81,  p.  262,  Plate  12,  Fiffs!  7-11. 
1881.     Olyptasler  occideiUatis  —  W.  and  Sp. ;  Revision  Palitocr.,  Part  II.,  p.  190. 


A  somewhat  larger  species  than  the  preceding.  Calyx  broadly  sub- 
turbinate,  abruptly  spreading  from  the  infrabasals ;  sides  slightly  convex ; 
plates  thin.  The  brachials  of  the  calyx  have  on  their  outer  or  dorsal  surface 
a  prominent  rounded  ridge,  covered  by  indistinct  longitudinal  striae,  and 
their  inner  or  ventral  side  has  a  deep,  semi-circular  groove.     From  both 


iil 


i.H 


(! 


TIIYSANOCRINID^E. 


195 


sides  of  Uic  ridge,  small  radiating  lines  pass  out  to  the  interbracliiuls,  form- 
ing triangles  of  wliicli  the  intervening  spaces  are  granular  or  covered  with 
fine  striations.  Stronger  ridgen  pass  from  the  radials  to  adjoining  basals, 
where  two  of  them  meet,  and  proceed  as  a  single  ridge  to  the  infruljasiils. 
The  latter  ridges  form  around  the  column  a  sharply  defined  pentagon,  who.«e 
salient  angles  lie  in  a  radial  direction. 

Infraba^als  of  moderate  size,  forming  a  narrow  belt  around  the  column, 
which  is  visible  in  a  side  view.  Basals  large,  without  nodes,  rapidly  spread- 
ing. Radials  larger  than  the  costals,  second  costals  narrower  than  the  first. 
Arms  apparently  ten,  of  which  in  mature  specimens  the  six  or  seven  lower 
plates  are  incorporated  ;  arm  plates  comparatively  large,  elongate,  and 
slightly  wedge-form.  Interbrachial  plates  large;  arranged:  1,  2,  3.  3,  with 
a  fifth  row  at  the  level  of  the  arm  bases.  Anal  interradius  considerably 
wider,  having  three  plates  in  the  second  row,  and  four  in  the  third ; — there 
being  no  continuous  row  of  anal  plates  or  any  sort  of  elevation.  Intcrdis- 
tichals  five  to  seven.  Ventral  disk  unknown.  Column  round  ;  axial  canal  of 
moderate  size ;  pentalobate,  the  lobes  directed  radially. 

Horizon  and  Locality,  —  Niagara  group;  Waldron  and  ITartsville,  Tnd. 

Ti/pes  in  the  American  Museum  Natural  History,  New  York. 

Bemar/i's. — This  species  differs  from  T/ii/sanucriiuis  inornutiiti  in  the  larger 
size  of  the  infrabasals,  the  arrangement  of  the  plates  of  the  anal  side,  the 
absence  of  an  anal  ridge,  and  in  the  general  ornamentation  of  the  plates. 

Ghjptastcr  occklentalis  (var.)  incrchescens  is,  in  our  opinion,  not  sufficiently 
distinct  to  be  ranked  as  a  variety. 


? 


»l 


Thyaanocrinus  brachiatus  Hall. 
Plate  XVIII.  Fig.  7. 

1852.     Olj/p/as/t-r  iraeHafiis  —  'nuu.  ;  Pnlirniit.  N.  York,  Vol.  IT.,  p.  187,  Tlatc  41,  T'li;.  i. 
18S1.     G/i/pliis/er  briickiiilus  —  W.  and  Sr. ;  llevisioii  Pulujocr.,  Part  II.,  i).  I'JC  (Proceed.  ."Vcad.  Nat.  Sci., 
Pliila.,  p.  370). 

Calyx  subglobose,  having  very  strong  radial  ridges  which  bifurcate  at 
both  ends.  The  lower  branches  proceed  to  the  basals,  and  produce  a  well 
defined  pentagon,  subdivided  into  five  nearly  equal  fields  by  another  row  of 
ridges;  the  upper  branches  follow  the  distichals,  and  pass  into  the  arms. 
The  general  surface  without  ornamentation. 

Infrabai3als  small,  but  exposed  beyond  the  column,  and  visible  even  in 
a  side  view.      Basals  of  moderate  size.     Radials  deeply  notched  for  the 


:/l 


196 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


reception  of  the  first  interbniciiinl,  tlieir  laterftl  faces  coininirntively  short. 
Costiils  Hiimller  tliiin  the  radiiils.  Anns  ten,  long,  slemler,  somewhat  Uatttned 
on  tlie  baclt ;  the  three  proximal  plates  take  part  in  the  eal^x,  are  curved 
like  the  free  plates,  and  are  but  little  larger.  The  first  free  brachial  is  rectan- 
gidar,  but  the  succeeding  ones  gradually  turn  into  cuneato,  interlock,  and 
fnialiy  change  to  biscrial,  with  the  upper  and  lower  faces  parallel.  Pinnules 
long  and  closely  packed.  Interbrachials :  1,  2,  2.  Anal  side  wider,  the 
plates  in  three  ranges,  divided  by  a  vertical  row  of  anal  plates ;  the  lower 
one  of  the  same  size  as  the  radials;  the  others  smaller,  decreasing  in  size 
upwards.  Structure  of  the  ventral  disk,  and  form  of  the  anus,  unknown. 
Column  pentangular. 

Ilorl-ion  and  LovaJ'ttij.  —  Niagara  group  ;  Lockport,  N.  Y. 

JiiiKarkn.  —  Our  description  and  figure  are  made  from  Hall's  typical 
specimen  *  in  the  American  Museum  of  Natural  History,  New  York,  after 
clearing  uway  the  matrix,  which  brought  to  light  the  pinnules  and  exposed 
the  calyx  plates.  That  Glijptadcr  is  generically  identical  with  T/n/saiiocriniis, 
nobody  will  doubt  after  comparing  our  figure  (Plate  XVIII.  Fig.  7)  with  that 
of  Thi/sanocriims  lilUfurmls  (Plato  XVIll.  Fig.  4). 


(?)  Thyaanoorlnus  Halli  (Lyon). 
Plate  XIII.  Figs.  9a,  h. 

ISCl.    Modomiiiis  Iliilli  —  Lyon  ;  I'rocred.  Arail.  Nat.  Sci.  Pliilii,,  p.  412,  Plate  4,  Figs.  5a,  i. 
ISSl.     (?)  H/io,/arriiiii.i  IJnlli—W.  and  Si'.  |  Iti'visiou  I'ala'ocr.,  Part  II.,  p.  212. 

A  large  species.  Calyx  vasiform,  a  little  wider  than  high,  rounded  below, 
the  sides  convex;  the  interradial  spaces  slightly  flattened,  and  the  radial 
plates  rather  sharply  elevated,  which  gives  to  the  cross-.'icction  a  subpentan- 
gular  outline.  Surface  of  the  plates  smooth,  the  suture  lines  distinct  but  not 
channeled. 

Infrabasals  visible  beyond  the  column ;  the  columnar  attachment  large, 
circular,  its  outer  margin  .surrounded  by  well-defined  radiating  striae.  Basals 
large,  a  little  convex ;  four  of  them  pentangular  or  nearly  so,  the  upper 
angles  almost  meeting  the  interbrachials,  sometimes  slightly  touching  them ; 
the  fifth  plate  pentangular,  broadly  truncate  above.  Eadials  and  costals 
wider  than  high,  gradually  decreasing  in  size  upwards.  Of  distichals  only 
two  are  preserved,  and  only  in  one  division  of  two  of  therays.   There  are  only 

•  Figured  by  Hall.    New  York  Pateont.,  Vol.  II.,  Plate  41,  Fig.  4. 


TIIYSANOCRINin.'E. 


197 


Mix  interbrnchiiilH  shown,  nrranged  :  1,  2,  3 ;  but  tlicro  were  probably  others 
above.  Tiie  anal  inturrailiiis  apparently  has  two  plates  in  the  second  row, 
but  the  nuJdle  one  of  the  next  row  extends  half  way  down  into  the  second. 

Jlwhon  and  Lucu/ltij.  —  Ningara  group  (?) ;  near  Louisville,  Ky. 

Jioiiarks. — Tho  ti/pi;  specimen,  which  was  said  to  be  in  the  Knapp  col- 
lection, cannot  bo  found.  Tho  two  specimens  hero  figured,  from  the 
Borden  Institute  of  New  Providence,  Ind.,  are  both  somewhat  abnormal  and 
quite  fragmentary,  ond  leave  some  doubt  as  to  the  generic  relations  of  the 
species.  Not  only  is  tho  anal  plato  followed  by  only  two  plates,  but  the  first, 
regular  interbruchial  occasionally  touches  the  basals. 


PTYCHOCRINUS  W.  and  Sr.  (Emend.). 

188S.     W.  mid  Sr. ;  Rcvismii  riilirocr.,  Tnrt  III.,  p.  99;  nlso  rriicocd.  Acnd.  Nnt.  Spl.  riiiln.,  p.  321. 

Sjii.  <r/y/i/orriiiii.i(m  pint) — lUi.i.,  IS72,  iiHli  Hep.  N.  Ycnk  Slate  fiih.  Nut.  Hist.,  p.  ;!li7;  nlso 

.MilkTiind  Dvcr,  1878,  .louiii.  t'incin.  Sdc.  Nat.  Hint.,  I'late  1,  Fit;.  111. 
Sjii.  (liiiiruiriiiiii  (ill  purl)  —  8.  A.  .\lll,i.EU  ;  lSb3,  Jourii.  Ciiiciii.  Soc.  Niit.  Hist.,  p.  228  ;  mid  1889 

N.  Ainer.  Geol.  and  l'u!a-<iiit.,  p.  270. 

Specimens  small;  in  form  and  mode  of  ornamentation  resembling  Ghjpto- 
crinus.  The  radial  plates  marked  by  a  well  defined  ridge,  which  passes  up 
and  down  tho  median  line  of  tho  plates,  giving  to  the  interradial  spaces 
a  somewhat  depressed  appearance. 

Infrabasals  five,  small,  but  generally  visible  beyond  the  column.  Basals 
five,  large ;  four  of  them  hexagonal,  the  posterior  one  heptagonal,  truncate 
above.  Radials  and  costals  of  nearly  equal  size.  Costals  two.  Disticbals 
vaiying  in  number,  curved  like  arm  plates.  Arms  ten  to  twelve,  rather 
delicate,  and  uniserial.  Pinnules  strong.  Interbrachials  and  interdistichals 
not  numerous,  tho  plates  definitely  arranged.  Posterior  side  with  a  longi- 
tudinal row  of  anal  plates  forming  a  ridge.  The  first  anal  plate  in  a  line 
with  the  radials,  and  always  succeeded  by  a  row  of  three  plates,  —  a  second 
anal  and  two  interbrachials.  Structure  of  ventral  di.sk  imperfectly  known. 
Column  cylindrical  ;  axial  canal  large,  pentalobate,  the  lobes  directed 
radially. 

Distribution.  —  Restricted  to  the  Trenton  and  Hudson  River  groups  of 
America. 

Type  of  the  genus  :  Ptijchomnus  splendcns  (S.  A.  Miller). 

Rcmarls.  —  Pt)/chocr!inis  differs  from  Tlnjsanocrinus  in  having  delicate 
uniserial  arms;    from  Edcocrinus  in  the  definite  arrangement  of  its  inter- 


:i 


198 


TlIK  C'UIXOIDKA   CAMKUATA  OK   NOHTII   AMKHICA. 


rndiiil  platuH,  uiid  in  linvuig  tlu'Mo  ruHtiii^  agaiiisl  tliu  riuliiilN;  fiuux  f,'li/j)tO' 
crinuH  in  liiiving  iniVa basilic,  and  an  anal  plate  in  contact  wilii  lliu  bamds. 

S.  A.  Miller,  in  IhUll,  arranged  a  number  of  Hpecies  under  a  propoHed 
genuH  (IdiiroLrinus,  wliicli,  liiie  Iuh  (lljipUnrinna,  cnibruceH  ii  variety  of  fornix, 
containing  Hpecies  of  Ititiovi'nntK,  O'lyjitocriiiiin,  and  a  tliird  form,  for  wliich 
we  i)roposed  tho  name  I'ti/r/iocrlnns,  whU  MWlvr'n  "  Cittiirorrliniti"  sjjltiKlnis 
tts  typo.  Wo  hIiouUI  have  preferred  to  accept  for  tlie  latter  Miller'«  name 
Gmrwvinua,  if  ho  liad  not  expressly  selected  as  the  type  of  his  genus  Hall's 
"  Gbjiitovriiiua"  Oimdli,  which  is  a  typical  Jiiiiocrtnua. 

*'  GJijIilovrlnus" prlnruH  E.  IJillings,  which  Walter  R.  Billing^  supposed  to 
have  infrabasals,  ond  which  wo  placed  provinionally  under  rtydiomnua,  hua 
sinco  been  referred  by  us  to  rd'iyli/jjtocrinun, 

Ftyohoorinua  splendens  (S.  A.  Millkk). 
PMe  XVIII,  Fi</s.3n,b. 

18S3.     Gaurocrinut  tplendem  —  S.  \.  Miller;  Jourii,  Ciiiciii.  Soc.  Nnt.  Hist.,  Vol.  VI.,  p.  230,  Plate  11, 

FiR.  3. 
1SS3.    Pti/cliocrinHi  tptemhna  —  W.  niid  Si'.;  Kovisioii  I'lilitocr.  I'lirt  III.,  p.  101. 
1880.    (liiunii'riiiui  ipleiident  —  8.  A.  Miller;  N.  Amer.  Gcul.  mid  Piiliroiit.,  \i.  247. 

Calyx  elongate,  obconical ;  cress-section  pentangular  with  concave  sldc^. 
Tho  plates  of  the  rays  folded  along  tho  median  lino,  so  as  to  form  broad, 
rounded  ridgo.s,  from  which  branches  proceed  to  the  basals,  meeting  there 
smaller  ridges  from  the  infrabasals.  Surface  of  plates  studded  with  rather 
conspicuous,  elongate  tubercles,  of  which  a  transverse  one  passes  over  the 
suture  of  two  adjoining  radials  without  touching  the  radial  ridges.  The  first 
interbrachials  have  seven  tubercles,  a  central  one  surrounded  by  six  others ; 
the  latter  occupying  the  outer  margins,  resting  in  part  upon  adjoining  plates. 
The  higher  interbrachials  have  only  a  central  tubercle. 

Infrabasals  small,  only  their  extreme  upper  points  visible  in  a  side  view. 
Basals  large,  higher  than  wide  ;  the  posterior  one  broadly  truncated.  Radials 
a  little  larger  than  the  basals,  about  as  long  as  wide.  First  costals  some- 
wliat  longer  than  wide,  and  hexagonal ;  the  upper  angles  of  the  axillarics  not 
truncated,  tho  interdistichals  not  touching  them.  Distichals  twelve  to  four- 
teen, of  which  the  three  to  four  lower  ones  take  part  in  the  calyx,  the 
succeeding  ones  being  free  arm  plates ;  the  upper  one  gives  ofT  two  arms, 
which  remain  simple.  Arms  delicate,  gradually  tapering  to  a  slender  point ; 
composed  of  a  single  series  of  rather  long,  wedgeform  joints.     Pinnules 


TUVSANOCRINin.E. 


190 


stout,  wlflely  no|mratcil.  Tho  firnt  pitimilc,  wliicli  in  fixo<l,  more  erect,  ami 
Htroiij^or  tliiin  tho  othcru,  in  given  olT  tVom  tho  outer  wide  of  tho  Mecontl  din- 
tichiil,  tli(  M'conil  from  tho  inner  Hide  of  the  fourtii  phito;  nil  nncccudin^^ 
pliitoH  except  the  axillnricH  beinj(  pinnuIe-lK'uriiij^.  Interliracliiiil  npiiceH 
deeply  depressed;  llit'  li  •<t  pliito  liirge,  followed  l)y  two  Hiiudler  ones,  mid 
tlie,«e  by  three  in  the  third  row,  iind  others  iihove.  Anal  widi'  wider,  ><)nie- 
whnt  nti/nlar  aloii}^  tl/#  median  line;  tho  Cunt  nnal  plate  rcNtin;r  iijjon  the 
truncate  bnwil.  Internxiilarn<t  three,  in  two  rnnj^cH ;  each  ono  nuirked  hy 
a  Hniall,  central  tuhercle.  Construction  nf  disk  and  form  of  anus  unknown. 
C.duinn  round,  slicrlitly  taperinj^ ;  tho  nodal  joints  at  their  outer  ovlges 
faintly  crenulated  ;  axial  canal  huyo.  pentalolmte. 

Ilorhon  and  LmiUty.  —  Trenton  group ;  Cape  Girardeau,  Mo.,  and 
Alexander  Co.,  111. 

Ti/pvH  in  tho  collection  of  S.  A.  Miller,  Cincinnati. 


? 


187a. 

1873. 
1879. 

1881, 

1881. 
1883. 

1885. 


Ftyohoorinus  parvus  (ii ai.i.). 
Plate  XVIII,  Fi(js.  la,  h  and  2. 

nli/iiliirrhmn  pnrriii  —  Ham.;  T)c'»pr.  New.  Criii.,  (■/(•.,  Plalr  1,  l''i|f.   17  (Hitlunil  UiMriiiliiiii) ;  also 

mh  Hep.  N.  V,  State  C'ul).  Nut.  lli»t.,  p.  2i)7,  I'liil.'  V.,  I'if,'.  17. 
Oli/plijci-iiiHf  luirnii  —  MtKK;  I'lilu'oiit.,  Ohio,  Vol.  1.,  p.  3(1,  I'lali'  i.  Figs.  \a,  h. 
Gli/iiliii-riiiiif  iiiii/iiliiriii —  Mii.i.Kii  mill  Dveh;  Jouni.  Ciiieiii.  Soc.  Niil.  Hist.,  I'lalo  1,  Fi(f.  10. 
I  lll,/i,l,.-rim„  luinn,      \  _y;  „,„i  gp  .  Revisinn  I'uliiM.or.,  pMrt  IF,  pp,  1S8,  189;  mill  Amor. 
i  ah„,h;crum,  „mjHUm>   ■         j,,,,„,   y^j^  j>,>,.,_  y^,   y^y^^^    j.^,   i!,-,5-2flS. 
\  Ki-li'ui-riiim  yi-urilis       J 
Rf/ivrriiiH-i  i/niriliii  —  Wetiik.rdy;  Ciiicin.  Jinirii.  Nut.  Sci.,  Vol.  IV.,  Plnlp  2,  Fig.  3. 

titorriiius  piirriD     )  — 8.  A.  Mll.i.Kli,  Juuni.  Ciiieiu.  Sue.  Nat,  Iii>t.,  Vol.  VI,,  pp.  22t  niiil 
(Hrocriinii  aiiffii/iiria  )  2iOj  ami  1SS9,  North  AiniT.  Oeol.  and  I'ala'ont.,  pp.  217  miil  21H. 


(  (!/i//i/orriiiH.i  juirnin     \  • 
(  (liinroiriniia  aiiguliirit ) 

fPti/chorrinuH  /lurrnn      ) 
I't^i'hocriniit  uiujuUifis  ) 


PlUrhocnnm  parm,     \  _  y^  ^,„,  g,.  .  m,vi,ion  p„l„ocr ,  Part  III.,  p.  100. 


Of  small  size.  Calyx  obconical,  with  slightly  convex  sides ;  the  radial 
plates  marked  with  prominent  rounded  ridges,  which  extend  to  nearly  the 
fidl  width  of  the  plates ;  interbrachial  spaces  flat,  plates  very  slightly  con- 
vex and  without  ornamentation. 

Infrabasals  miinite,  only  the  outer  angles  of  the  plates  visible  beyond 
the  column.  Bnsals  large,  higher  than  wide  ;  their  surfaces  strongly  convex. 
Interbasal  sutures  deeply  depre.ssod,  and  the  depression  continued  to  the 
radials,  of  which  the  lower  ends  bend  inward.  Radials  somewhat  larger  than 
the  first  costals.  The  second  costals  of  similar  form  to  tho  radials,  only 
reversed,  being  angular  above  instead  of  below.  Distichals  2  X  10,  about  as 
wide  as  long,  the  upper  one  axillary.     Arms  four  to  the  ray,  free  from 


>  I 


200 


THE  CRINOIDEA  CAIIERATA  OF  NORTH  AMERICA. 


the  first  or  second  palmar;  composed  of  wedgoshaped  joints,  wliicli  arc  as 
long  as  wide,  and  rounded  on  the  back.  Pinnules  stout,  well  separated. 
Interbrachial  spaces  depressed,  flat ;  the  first  plate  of  the  regular  sides  as 
large  as  the  costals ;  followed  by  two  plates  in  tho  second  row,  and  a  number 
of  others,  which,  though  well  defined,  are  more  or  less  irregular  in  their 
arrangement.  Anal  side  wider,  divided  by  a  longitudinal  row  of  hexagonal 
plates ;  the  plates  at  each  side  of  this  row  about  as  numerous  as  the  whole 
series  of  plates  of  the  four  regular  sides.  Interaxillaries  five  or  more.  Con- 
struction of  the  ventral  disk  unknown.  Column  round ;  axial  canal  of 
medium  size. 

IIoiizoH  and  Locality.  —  Hudson  River  group ;  Cincinnati,  0. 

Remarks.  —  Ghjptocrinus  ( Gaurocrinus)  aiujiilaris  Miller,  and  lietcocrimts 
gracilis  Wethcrby,  are  undoubtedly  synonyms  of  Hall's  "Glijptocrinns" 2)ar- 
viis.  Mr.  Miller  was  good  enough  to  send  us  two  specimens,  which  he  had 
himself  identified  .as  "  Gaurocrinus  "  aurjularis,  and  Mr.  Vaupel  kindly  loaned 
us  the  type  of  Ecteocrinm  gracilis.  Both  specimens  are  figured  on  Plate 
XVHL,  and  a  comparison  of  them  with  Hall's  type  of"  Glijpfocrimis'^  i^arvus 
will  prove  that  they  all  represent  one  species. 


HYPTIOCRINUS  W.  and  Sp. 

(uTTTios,  bending  back ;  Kpivov,  a  lily). 

1892,    W.  and  Sr.;  Am.  Geologist,  Vol.  X.  (September),  p.  138. 

Syu.  Ci//i/iocriiiiis  S.  A.  Milleu  (October  20,  1892) ;  Adv.  Sheets,  18th  Rep.  Geol.  Surv.  Indiana, 
p.  50. 

Name  referring  to  the  character  of  the  arms,  which  hang  downward. 
Calyx  depressed,  wheel-shaped.  Infrabasals  five,  small.  Basals  five,  four  of 
them  equal,  angular  at  the  upper  end  ;  the  posterior  one  truncated  by 
the  anal  plate.  Radials  comparatively  small,  all  heptngonal.  Costals  two. 
Fixed  brachials  rather  large,  except  the  first  costals,  which  are  quite  short, 
and  quadrangular.  Distlchals  one,  the  distal  face  broadly  truncated;  fol- 
lowed by  several  sharply  cuneate  pieces,  which  interlock,  and  of  which  the 
two  or  three  proximal  ones  (in  the  type)  lake  part  in  the  calyx.  Arms 
stout,  probably  biserial,  and  pendent,  to  judge  from  the  arm  openings,  which 
are  directed  obliquely  downward.  First  interbrachials  of  the  regular  sides 
very  large,  succeeded  by  several  rows  of  sriialler  pieces.  Anal  plate  touching 
the  biTsak  and  rising  above  the  radials;  supporting  three  much  smaller 
plates  and  others  above.     Ventral  disk  depressed ;  the  posterior  oral  and  the 


TIIYSANOCRINIDiE. 


201 


radial  dome  plates  spinous;  the  anus  excentric  and  at  the  top  of  a  large 
protuberance. 

Distribution.  —  So  far  as  known,  restricted  to  the  Niagara  group  of 
Indiana. 

liemarks.  —  The  genus  has  its  closest  relations  with  Tliysanocrinus,  from 
which  it  differs  in  the  depressed  form  of  the  calyx,  the  pendent  arms,  and 
in  the  spine-bearing  disk. 

Hyptiocrinus  typus  W.  and  Sp.  (nov.  spec). 
Plate  XIX,  Figs.  6a  to  c. 

1892.     W.  and  Sp.  ;  Am.  Geologist,  Vol.  X.  (Scptniibd),  p.  13S. 

Syn.  C^phocrium  Goi-byi  S.  A.  Milleu  (October  20,  1S92).     Adv.  Sheets  18th  Rep.  Geol.  Siirv. 
Indiana,  p.  51,  Plate  7,  Figs.  14, 15,  16. 

Specimens  of  medium  size.  Calyx  wheel-shaped,  nearly  once  and  a  half 
as  wide  as  high.  Dorsal  cup  broadly  obconical  to  the  top  of  the  costals,  then 
flanging  outward  and  somewhat  downward.  Arm  regions  not  lobed,  but  the 
upper  margins  of  the  interbrachial  and  interdistichal  spaces  formed  into 
sharp  edges  by  means  of  corresponding  depressions  in  the  dorsal  cup  and 
tegmen.  Costals  and  distichals  marked  by  rounded,  longitudinal  ridges, 
following  the  median  line  of  the  plates.  Veutral  disk  a  little  higher  than 
the  dorsal  cup,  its  lateral  margins  slightly  bulging,  the  lower  edge  some- 
what projecting  over  the  upper  margin  of  the  dorsal  cup.  Plates  flat,  their 
surface  in  well  preserved  specimens  densely  covered  by  fine  granules. 

Infrabasals  small,  hidden  by  the  column ;  forming  a  flat  pentngonal  disk. 
Basals  rather  large,  about  as  wide  as  hmg ;  curving  abruptly  upwards  ;  the 
posterior  one  slightly  truncated  at  the  upper  end ;  the  interbasal  suture  lines 
distinctly  grooved.  Radials  twice  as  wide  as  long,  their  proximal  ends  dis- 
tinctly angular.  First  costals  much  shorter  and  narrower  than  the  radials ; 
quadrangular.  Second  costals  longer  and  a  little  wider  than  the  first ;  their 
lateral  faces  short;  the  sloping  upper  faces  making  a  right  angle.  First 
distichals  as  large  as  the  axillary  costals,  followed  by  two  or  three  cuneate 
plates  in  the  calyx,  which  slightly  interlock.  Structure  of  the  free  arms  not 
observed,  but  they  were  apparently  biserial  and  quite  heavy  and  pendent. 
First  interbrachials  of  the  regular  sides  the  largest  plates  of  the  calyx,  rising 
to  the  height  of  the  first  distichals,  and  being  succeeded  by  two  rows  of  two 
plates  each.  The  anal  plate  a  little  higher  than  the  radials,  supporting  three, 
two,  and  two,  smivUer  plates.    Interdistich.als  one,  small.    Posterior  oral  nearly 

26 


n 


'It 


H 
'11 


■1 


202 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


I 


central,  large,  and  extended  into  a  heavy,  short  spuie ;  the  other  four  orals 
proportionally  small  and  almost  flat.  Radial  dome  plates  represented  by 
plates  of  a  first  and  second  order,  those  of  the  latter  by  two  or  throe  plates 
to  each  division,  alternately  arranged ;  all  large  and  spine-bearing.  The 
spines  near  the  outer  margins  of  the  disk  project  obliquely  outward,  and  are 
visible  from  a  dorsal  view  of  the  calyx.  Interambulacral  plates  numerous,  of 
the  size  of  the  smaller  orals,  and  irregularly  arranged.  Anus  excentric,  at 
the  top  of  a  large  ovoid  protuberance,  rising  conspicuously  above  the  general 
plane  of  the  disk. 

Horizon  and  Loealitij.  —  Niagara  group ;  St.  Paul,  Shelby  Co.,  Ind. 

Ti/pe  in  the  collection  of  Wachsmuth  and  Springer. 


IDIOCRINUS  W.  and  Sp.  (nov.  gen."). 

(iSios,  peculiar;  Kplvov,  a  lily). 

1S92.     W.  and  Sp.  ;  Am.  Geologist,  Vol.  X.  (Scptcmbci),  p.  135. 

Syu.  Gii:iicri/ius  S.  A.  Miller  (October  20,  1392) ;  Adv.  Sheets,  18th  Rep.  Geo!.  Surv.  Indiana, 
p.  49. 

Infrabasals  apparently  five,  extremely  small,  placed  at  the  bottom  of 
a  more  or  less  deep  concavity,  and  completely  hidden  by  the  column.  Basals 
five,  very  large ;  the  posterior  one  truncated  by  the  anal  plate.  Radials  quite 
large ;  three  of  them  heptagonal,  the  two  adjoining  the  anal  side  hexagonal. 
Costals  two,  very  short;  the  lirst  quadrangular;  the  second  pentangular, 
the  upper  angle  rather  obtuse.  Distichals  two  in  the  calyx ;  short.  Inter- 
radial  areas  at  all  sides  composed  of  a  single  large  plate,  which  rises  to  the 
top  of  the  dorsal  cup  ;  that  of  the  anal  side  resting  upon  the  basals,  the  four 
others  upon  the  sloping  upper  faces  of  the  radials.  Ventral  disk  quite  vari- 
able in  form ;  covered  by  a  large,  probably  anchylosed  oral  pyramid.  The 
ambulacra  tegminal ;  the  interambulacral  spaces  formed  of  single  plates, 
of  which  the  posterior  one  is  perforated  by  the  anus,  which  is  excentric. 
Arms  and  column  unknown. 

T^pe.  —  Idiocrimts  elongatus. 

Distribution.  —  So  far  as  known,  restricted  to  the  Niagara  group  of 
America. 

licmarls.  —  This  genus  differs  from  all  other  dicyclic  Camerata  in  having 
a  single  plate  in  the  anal  area,  in  its  central,  undivided  oral  pyramid,  and  in 
having  but  one  interambulacral  plate  to  each  side  of  the  disk. 


ft' 


TIIYSANOCRINIDiE. 


203 


Idioorinus  elongatus  W.  mid  Sp. 
Plate  XVIII.  Fi(js.  Sa  to  c. 

1892.    W.  and  Sr.,  Am.  Geologist,  Vol.  X.  (Sei)teiiibei),  p.  13G. 

Syii.  Guzucrimis  iiiornalus  S.  A.  Milieu;  Adv.  Sheets  IStli  Rep.  Geol.  Surv.  ludiaiin,  p.  49,  Pln(o 
5,  Figs.  9,  ]0,  15,  16,  17  (published  October  20),  1S92. 

A  small  species.  Calyx  obconical ;  the  ventral  clii<k  almost  on  a  level 
with  the  upper  margins  of  the  dorsal  cup;  the  cup  deeply  excavated  at  the 
bottom,  the  basals  forming  a  large  funnel-shaped  pit.  Plates  without  orna- 
mentation and  flat,  except  the  radials,  which  are  a  little  convex,  and  rise 
slightly  above  the  plane  of  the  cup.     Suture  lines  not  grooved. 

Infrabasals  minute,  constituting  the  bottom  of  the  basal  concavity.  Basals 
extremely  large  and  elongate,  the  lower  end  curving  abruptly  inward,  and 
forming  a  sharp  edge  around  the  bottom  of  the  calyx ;  the  exposed  part  of 
the  plates  rising  to  more  than  one  third  the  length  of  the  dorsal  cup.  Ivadi- 
als  once  and  a  half  as  wide  as  long,  distinctly  angular  at  their  lower  faces  ; 
the  two  posterior  plates  hexagonal,  being  distinctly  truncated  by  the  anal 
plate.  Costtals  together  less  than  half  the  size  of  tiie  radials;  the  first  linear; 
the  second  a  very  little  longer,  and  its  upper  angles  quite  obtuse.  Dis- 
tichals  two,  somewhat  higher  and  wider  than  the  costal.s ;  the  upper  semi- 
free.  Interbraehials  one,  those  of  the  four  regular  sides  resting  upon  the 
deeply  sloping  sides  of  the  radials,  the  anal  one  upon  the  narrowly  truncated 
basal ;  all  extending  to  the  upper  end  of  the  calyx,  and  all  longer  than  wide. 
Arms  apparently  ten,  their  dorsal  faces  flat. 

Ventral  disk  but  slightly  elevated,  consisting  of  five  large,  oblong,  trian- 
gular plates,  one  to  each  area,  which  do  not  meet  in  the  centre,  but  leave 
a  moderately  large,  pentalobate  open  space  at  the  summit.  Tlic  sides  at  the 
lower  ends  of  the  plates  to  two  thirds  their  length  are  not  in  contact,  but 
leave  elongate  spaces,  which  were  apparently  occupied  by  the  ambulacra ; 
the  lateral  edges  are  tdightly  serrated,  and  bend  outward  for  the  reception  of 
the  covering  pieces.  Near  the  summit,  the  plates  meet  in  a  similar  manner 
as  the  deltoids  of  the  Blastoid  genus  Pcntrcmites,  by  means  of  lateral  pro- 
cesses, and  these  are  converted  into  grooves  which  comnuinioate  with  the 
vacant  .space  in  the  centre.  The  structure  is  such  as  to  indicate  that  the 
ambulacra  followed  these  grooves  before  entering  the  peristojiie,  and  that 
the  centre  was  covered  by  an  oral  pj'ramid,  as  in  the  allied  Idiocrinm  vcntrU 
casus,  in  Avhich  the  pyramid  was  found  in  position.     The  posterior  inter- 


^ 


(  :  i 


I  t"     I 


i1  ' 


i^i 


204 


THE  CRIXOIDEA  CAMERATA  OF  NORTH  AMERICA. 


ambulacral  plate  is  somewhat  wider,  and  perforated  by  the  anus  to  such  an 
extent  as  to  leave  only  a  narrow  skeleton  at  the  lateral  margins. 

Gazacrinm  Miller  is  identical  with  Idiovvimis,  the  latter  name  having 
priority.  Miller  described  the  genus  as  monocyclic  instead  of  dicyclic,  and 
he  speaks  of  a  "  vault  sustained  by  a  specialized  frame  work  with  ambulacral 
canals  connecting  tlie  arms  with  the  central  orifice."  This  is  misleading,  for 
the  plates  exposed  at  the  oral  surface  are  true  plates  of  the  disk,  and  the 
open  spaces  which  apjjcar  in  the  specimens  were  closed  by  orals  and  ambu- 
lacral plates.  There  was  no  central  orifice,  the  peristome  being  covered  us 
in  all  other  Camerata. 

Horizon  and  Locality.  —  Upper  part  of  Niagara  group ;  St.  Paul,  Shelby 
Co.,  Ind. 

Ty2)e  in  the  collection  of  Wachsmuth  and  Springer. 

Remarks.  —  Mr.  Miller,  in  describing  the  arm  plates  of  this  species, 
states  they  are  long,  and  their  edges  "  are  transversely  serrated  on  the 
inside,  half  the  depth  of  the  plates."  We  observed  this  structure  in  our 
specimen,  and  were  at  first  inclined  to  regard  the  edges  as  formed  of  small 
side  pieces,  and  so  described  them  in  the  "  American  Geologist."  Since  then 
on  further  cleaning  the  specimen,  we  have  become  convinced  that  the  parts 
in  question  are  mere  extensions  of  the  arm  plates,  which  are  short,  and  that 
the  line  of  union  is  slightly  gaping  to  facilitate  motion. 

Another  point  in  Miller's  description  should  be  noticed.  He  says:  "There 
are  three  longitudinal  furrows  on  the  inside  of  each  radial  series,  shown  at 
the  top  of  the  secondary  radials;  this  gives  fifteen  furrows  at  the  top  of  the 
secondary  radials,  one  in  the  middle  of  each  plate,  and  the  other  at  the 
suture ;  "  and  he  alludes  to  this  as  a  peculiarity  entirely  new  to  him.  He 
evidently  misunderstood  the  structure,  for  our  specimen  clearly  shows  but 
one  furrow  to  each  brachial,  of  which  those  from  the  distichals  unite  upon 
the  axillary  costals  at  the  extreme  edge  of  the  disk.  The  supposed  marginal 
furrows  do  not  enter  the  disk,  and  are  mere  depressions  at  the  lateral  margins 
of  the  distichals,  formed  by  the  highly  projecting  serrated  edges  of  the 
ambulacral  furrows  at  each  side. 


TIIYSANOCKINID^E. 


205 


IdiOCrinUS  ventriOOSUS  W.  ami  Sr.  (nov.  spec). 

Plate  XVIII.  Fi(js.  9a,  b. 

A  very  small  species.  Calyx  as  wide  as  high ;  height  of  dorsal  cup  about 
equal  to  that  of  the  tegmen  ;  the  former  bowl-shaped,  the  cup  obtusely 
pyramidal.  Plates  smooth ;  the  radials  and  costals  somewhat  longitudinally 
convex,  causing  a  small  depression  of  the  interbrachial  spaces.  Suture  lines 
slightly  grooved. 

Infrabasals  extremely  small,  and  completely  covered  by  the  column ; 
placed  at  the  bottom  of  a  small  circular  cavity,  formed  by  the  lower  ends  of 
the  basals.  Basals  of  moderate  size,  their  lower  ends  incurving  and  forming 
the  sides  of  the  concavity,  their  upper  angles  slightly  bending  upwards. 
Radials  once  and  a  half  as  large  as  the  two  costals  together,  and  twice  as 
wide  as  long ;  three  of  them  hcptagonal,  the  two  posterior  ones  hexagonal. 
First  costals  quadrangular,  much  narrower  than  the  radials,  and  three  times 
as  wide  as  long;  the  second  of  nearly  the  same  width  as  the  first,  but  longer. 
Distichals  narrower  and  shorter  than  the  second  costals.  Interbrachials  large, 
subelliptical ;  that  of  the  anal  side  a  little  wider,  and  slightly  truncating  the 
posterior  basal.  Oral  pyramid  convex,  a  very  little  tumid,  extremely  large 
for  the  size  of  the  species,  perfectly  closed  at  the  summit,  and  the  inter-oral 
sutures  obsolete.  The  outer  surface  of  the  pyramid  is  covered  with  well 
defined  radiating  ridges,  which  proceed  from  the  middle  of  the  plate  to  the 
outer  margins,  increasing  in  height  and  width  as  they  pass  outward.  Ten  of 
these  ridges  are  prominent,  and  project  outward  around  the  circumference, 
thus  giving  to  the  plate  the  aspect  of  a  ten-rayed  star.  The  inner  floor  is 
excavated  centrally,  and  there  are  five  deep  grooves  passing  out  in  a  radial 
direction.  The  interambulacral  plates  long,  slender  and  cuneate,  attached 
with  their  sharp  upper  ends  to  the  inner  margins  of  the  orals.  They  project 
outward  so  as  to  form  at  their  sides  open  spaces  for  the  reception  of  the 
ambulacra.     Other  parts  unknown. 

Horizon  and  Locality.  —  Upper  part  of  Niagara  group ;  near  St.  Paul,  Ind. 

Type  in  the  collection  of  Wachsmuth  and  Springer. 

Remarks.  —  The  oral  pyramid  of  this  species,  which  is  found  occasionally 
detached  from  the  body,  was  regarded  by  Miller,  Benedict,  and  ourselves,  as 
probably  representing  the  ventral  structure  of  a  Pisocrinus.  This  appeared 
quite  plausible,  as  it  was  expected  from  analogy  that  in  Pisocrimis,  as  in  the 


^ 


206 


TIIK  CRIXOIDKA  CAJIKRATA  OF   NORTH  AMERICA. 


allied  Si/mhathocrinm,  Allmjccrinus  and  ILiplocrinus,  the  ventral  disk  consisted 
of  onils  only,  and  the  plate  fitted  approximately  upon  the  cup  of  one  of  the 
species,  which  occurs  in  the  same  bed.  A  well  preserved  oral  pyramid  of  this 
genus  is  figured  on  Plato  III.  P'ig.  15,  which  may  belong  to  this  species. 

(-0  Idioorinus  immaturus  (Hall). 
Plate  XVIII,  Figs.  10a,  h,  c. 

1S51.     Thtjmmrrinm  immalunix —  IIai.l;  Pnltcont.  N.  York,  Vol.  11.,  p.  191,  Plntc  42,  Figs,  lu-/ 

This  small  species,  so  far  as  known,  in  its  general  habitus  so  closely 
resembles  Idiocrimts  that  we  are  inclined  to  regard  it  as  belonging  to  this 
genus.  It  is  more  depressed  than  /  clonrjutus,  the  sides  of  the  cup  are  more 
convex,  the  base  more  concave,  and  the  costals  proportionally  higher. 
Neither  arms  nor  ventral  disk  are  known. 

Horizon  and  Lomllty.  —  Niagara  group  ;  Lockport,  N.  Y. 


(?)  Idiocrinus  tennesseensis  (Wouthe.n). 
Plate  XVIII,  Fifj.  11. 

1890.     C'li/roeriniis  feiiiies.ieeii.ih  —  WoRTiiENj  Gcol.  Rep.  Illinois,  Vol.  VITT.,  p.  0.">,  Plate  14,  Fig.  1. 

Dorsal  cup  apparently  obconical.  Plates  almost  flat,  and  without  orna- 
mentation ;  suture  lines  indistinctly  grooved, 

Infrabasals  three,  forming  a  slightly  projecting  rim  around  the  bottom  of 
the  calyx.  Basals  rather  large,  fully  as  high  as  wide,  three  of  them  pentan- 
gular, the  others  being  covered  by  matrix.  Eadials  one  fourth  wider  than 
long,  the  lower  faces  distinctly  angular.  Costals  two,  narrower  than  the 
radials  ;  the  first  quadrangular  and  extremely  short,  more  than  three  times 
as  wide  as  long ;  the  second  a  little  longer  than  the  first,  and  obtusely  an- 
gular above.  Distichals  two  in  the  calyx ;  the  proximal  one  as  long  as,  or 
longer  than,  the  axillary  costal ;  the  second  a  little  wider  than  the  free  arm 
lilatc's,  but  not  higher.  Arms  two  from  the  calyx,  moderately  stout ;  com- 
posed of  rather  long,  quadrangular  joints,  branching  (at  least  in  one  of  the 
arms)  from  the  fourth  free  plate.  Interbrachials,  as  seen  at  two  sides,  subel- 
liptical,  extending  to  the  full  height  of  the  first  distichals,  slightly  grooved 
longitudinally  at  the  median  line.  Stem  round,  the  nodal  joints  high,  the 
outer  faces  convex  and  somewhat  projecting.  All  other  parts  of  the  species 
unknown. 


TIIYSANOCRINlDiE. 


207 


Horizon  and  Locality.  —  Niiigara  group;  near  Clifton,  Wayne  Co.,  Tenn. 

Tt/2)e  in  the  Illinois  State  collection,  Springfield. 

Eeimn-h.  —  We  refer  the  above  species  to  this  genus  with  considerable 
doubt,  although  it  has  close  affinities  with  it  in  the  structure  of  the  dorsal 
cup;  but  it  differs  from  the  typical  form  in  having  three  rather  large, 
projecting  infrabasnls  —  that  having  apparently  five  —  and  the  plates  are 
completely  covered  by  the  stem.  Whether  it  has  the  same  sort  of  ventral 
disk  cannot  be  ascertained  from  the  specimen,  nor  do  we  know  anything 
about  the  structure  of  the  anal  side.  Worthen  referred  the  species  to  the 
monocyclic  genus  Ccntroctinus,  and  apparently  took  the  infrabasnls  for  a 
projecting  rim  of  the  basals. 


LAMPTEROCRINUS  Roemeb. 

I860.  F.  Roemeb;  Silur.  Fauna.  Wni.  Toiin.,  p.  37. 

1803.  Hall;  Trans.  Albany  Institute,  Vol.  IV.,  p.  202. 

1366.  S11U.M. ;  Trans.  Aciiil.  Sci.     Si.  Lcmis  (Cut.  Tnlitoz.  Foss.,  p.  378). 

18G8.  Hall;  2OII1  Ucp.  N.  York  States  Cab.  Nat.  Hist.,  p.  328. 

1S70.  Zittel;  Handb.  iler  Pabrontologie,  Vol.  I.,  p.  375. 

1881.  W.  and  Sp. ;  Revision  Pataocr,,  I'nrt  II.,  p.  199  (Proceed.  Acad.  Nat.  Sci.,  Philn.  1S81,  p.  373). 

1882.  De  Loriol;  Paleont.  Franfaiso,  Tome  XI.  (Crinoides),  p.  59. 

1885.     W.  and  Sp.  ;  Revision  I'alieocr.,  Part  III.,  p.  101  (Proceed.  Acad.  Nat.  Sci.  Pliila,,  p.  323). 
1889.    S.  A.  Miller  ;  N.  Anier.  Gcol.  and  Paliuont.,  p.  257. 

Syn.  A//tf«oc/-i««.<  —  Troost,  1850  (not  Agassiz,  ISIO),  Cat.  Foss.  Tcun.,  p.  00. 

Calyx  unaymmetrical,  elongate-obpyramidal,  the  rays  formed  into  tubular 
appendages  bearing  the  arms.  Ventral  disk  greatly  inflated  posteriorly,  and 
extended  into  a  large  tube,  pushing  the  centre  of  radiation  to  the  anterior 
side  of  the  calyx. 

Infrabasals  anchylosed,  fonning  a  large  spreading  cup.  Basals  five,  very 
large,  four  of  them  equal,  angular  above;  the  posterior  one  considerably 
higher,  and  truncated  at  the  upper  face.  Radials  very  large.  Costals  two, 
the  first  hexagonal,  the  second  supporting  at  one  side  a  lateral  arm,  at  the 
other  the  distichals.  The  higher  orders  of  radials,  from  the  distichals  up, 
are  curved  like  arm  plates,  and  with  the  covering  pieces  form  a  rigid  tube, 
from  which  small  arms  are  given  o(T  alternately  at  intervals.  In  the  typical 
species  the  distichals  consist  of  three  short  pieces,  the  upper  one  axillary, 
supporting  at  one  side  the  second  arm,  at  the  other  the  palmars,  of  which 
only  the  first  plate  has  been  observed. 

Interbrachials  large,  passing  uninterruptedly  from  the  dorsal  cup  into 
the  tegmen;    there  is  one  plate  in  the  first  row,  followed  by  two  in  the 


m 


I  t 


f 


208 


THE  CIUXOIUKA   CAMKRATA  OF  NORl'II  A5IKIUCA. 


Hcconil.  At  the  anal  side,  which  is  somewhat  wider,  the  first  oiial  plate 
rests  upon  tlip  basals,  and  supports  three  small  plates  in  the  next  range, 
which  are  succeeded  by  three  plates,  and  others  above.  Ventral  disk  asym- 
metrical, strongly  bulging  at  the  posterior  side,  and  supporting  a  large 
central  tube.     Orals  large,  excentric. 

Column  pentangular ;  axial  canal  small. 

Distvibntiun,  —  Niagara  group  of  America. 

Remarka.  —  We  only  recogni/e  Roomer's  typical  species.  Hall's  Lamp- 
tcrocrimts  iiiflalus  {Bahmocrlnm  sculptus  Troost  MS.)  has  never  been  described, 
and  the  figure  *  was  made  from  a  natural  cast,  of  which  the  anal  side  is 
not  seen.  LamjHcrocmus  parvus  t  was  also  described  from  very  imperfect 
nuiterial. 

Lumpterocr'mus,  by  its  asynnnetry,  and  the  position  of  its  anal  tube,  is 
very  closely  allied  to  Siphonocranta  ;  but  it  is  readily  distinguished  by  its  arm 
struuture. 

Lampterocrinus  tennesseensis  Kukmer. 

riatc  XIII.  Figs.  10a,  b,  c,  d. 

ISBO.     RoEMEli;  Silur.  Fiiuim  West.  Tcmi.,  p.  37,  I'late  4,  Figs.  \a,  b. 
1881.     W.  mill  Si>.;  UcvisioTi  I'liln'ncr.,  I'art  II.,  p.  201, 

Syii.  JIultiuocriiiiis  anilpliis  TuoosT  (Cutaloguc  uaiiip). 

Cal^'x  elongate,  more  than  once  and  a  half  as  high  as  wide,  decidedly 
asymmetrical.  Dorsal  cup  higher  than  wide,  spreading  abruptly  to  the 
middle  of  the  radials,  where  it  attains  almost  its  full  width ;  cross-section 
pentangular.  Plates  convex,  their  surface  ornamented  Avith  conspicuous 
radiating  ridges,  passing  from  the  centre  of  one  plate  to  the  centre  of  an- 
other—  there  being  one  ridge  for  each  side  of  the  plates  —  dividing  the 
surface  into  well  marked,  deeply  impressed  areas.  The  ridges  are  angular, 
knife-like,  their  edges  more  or  less  serrated ;  those  from  the  infrabasals  to 
the  basals,  and  thence  to  the  radials,  and  between  radials  and  costals,  and 
to  the  first  interbrachials,  are  more  prominent  than  those  of  the  higher  in- 
terbrachials,  but  the  centre  of  the  latter  is  raised  into  a  small,  sharp  node. 

Infrabasals  five,  completely  ancliylosod,  forming  a  small  cup;  the  suture 
linos  obliterated  by  extraordinary  secretion  of  calcareous  matter,  and  raised 
into  sharp  ridges,  passing  out  from  the  angles  of  the  column  to  the  lower 

•  28tli  Rep.  N.  York  State  Museum  Nat.  Hist.,  Plate  10,  Fig.  6. 

t  11th  Rep.  of  Gcol.  and  Nat.  Hist.  State  of  ludiaua,  Plate  15,  Fig.  6. 


i 

i 

): 

i 

I 

TIIYSANOCRINIDvE. 


209 


angles  of  the  basnls  ;    tho  truncated  part  sharply  pentangular,  and  com- 
pletely occupied  by  tho  column.     Basals  very  large,  ns  long  as  wide,  and 
angular  above;    the  posterior  one  considerably  lor^^er,  and  its  upper  face 
truncated.     Kadials  fully  twice  as  large  as  th"  first  costals,  and  somowlint 
larger  than  the  basals.     Second  costals  smaller  i    a\  the  first,  and  lacing  out- 
ward,  the  sides  slightly  incurving;  their  sloping  upper  faces  unecjual,  the 
shorter  side  bearing  a  lateral  arm,  and  the  longer  one  a  row  of  distichals. 
Tho  higlier  orders  of  brachials,  wiiich  are  roofed  over  l)y  rigid  covering 
pieces,  are  formed  into  tubular  appendages,  from  which  at  intervals  arndets 
arc  given  off  alternately.     The  second  arm  starts  from  the  third  distichnl. 
and  it  is  probable  that  each  succeeding  arm  is  given  off  from  the  third  plate 
of  successive  brachials.      The  appendages  are  preserved  in  the  specimens 
only  to  the  first  palmar.     Interbrachials :   1,  2,  3;  the  first  as  large  as  tho 
first  distichal;  those  of  the  second  and  third  row  much  smaller.     Anal  side 
a  little  wider  and  bulging  from  below  the  base  of  the  free  rays  upward-* ;  the 
anal  plate,  which  is  even  larger  than  the  first  radials,  is  followed  by  three  not 
very  large  plates,  and  these  by  successive  rows  of  three  plates  each,  which 
pass  into  tho  anal  tube ;  the  plates  of  the  middle  row  are  marked  l)y  a  con- 
spicuous angular  ridge,  which  extends  from  the  angles  of  the  column  to  the 
base  of  the  anal  tube,  and  runs  parallel  to  the  ridges  upon  adjacent  radials 
and  costals.     Ventral  disk  elevated ;   composed  of  few  rather  large,   eon- 
■c^x  or  slightly  nodose  plates,  which  are  continuous  with  the  interbrachials. 
Ihe  anal  tube  is  constructed  of  similar  somewhat  smaller  plates;  it  is  cen- 
tral,  but  bends  abruptly  to  the  anterior  side  of  the  calyx  ;  its  length  not 
known.     Orals  not  larger  than  the  other  plates  of  the  tegmen ;  they  are 
excentric,  being  pushed  completely  to  the  anterior  side.     Column  near  the 
calyx  sharply  pentangular,  with  a  small  node  at  the  angles  of  each  joint. 

Horizon  and  Localiti/.  —  Upper  part  of  the  Niagara  group  ;  Decatur  and 
Wayne  Cos.,  Tenn. 

Types  in  the  Mineralogical  Museum  at  Breslau,  Germany. 


SIFHONOCBINUS  S.  A.  JtiLLER  (redefined,  W.  and  Sp.). 

1883.     Mll-tKB;  Amer.  ReoloRist,  Vol.  I.,  p.  203;  and  1SS9,  Amer.  Genl.  and  Palirnnt.,  p.  281. 
Syn.  Euealyptocrimis  (?)  — McCiiESXEy,  1850;  Dcscr.  New  Sppcips,  p.  95. 

Syn.  0/y;)/om»KJ  — McCiiesset;  Cliicngo  Acad.  Sci.,  1S08,  Vol.  I.,  p.  23 ;  and  Hall,  ISfil ;  Rop. 
of  Progr.  Geol.  Surv.  Wise,  for  1860,  pp.  21  and  23 ;  and  UaU,  18G7 ;  20th  Rep.  N.  York  State 
Cab.  Nat.  Hist.,  p.  328. 

VI 


^ 


!     V 


r 


210 


THE  CRINOIDEA  CAMEUATA  OF  NOHTH  AMERICA. 


Knuwn  only  from  natural  casts  and  Impressions  fVom  the  natural  moulds 
in  the  rock.  Calyx  large,  oblong,  its  form  extremely  asymmetrical.  Dorsal 
cup  deeply  depressed  interradially,  the  rays  projecting  so  as  to  give  to  the 
calyx  a  strongly  lobed  outline.  Ventral  disk  generally  as  high  as  the  dorsal 
cup ;  its  posterior  side  inllated  from  below  the  brachial  zone  to  the  summit, 
forming  a  conspicuous  helmet-shaped  protuberance,  which  at  the  arm  regions 
not  only  occupies  the  whole  width  of  the  posterior  interradius,  but  encroaches 
largely  upon  the  left  posterior  lay,  not  involving  the  ray  to  the  right,  from 
which  it  is  separated  by  a  deep  groove.  This  protuberance,  as  seen  from  the 
casts,  grows  narrower  at  the  summit,  and  the  upper  part  either  bonds  directly 
upwards,  in  the  form  of  a  central  tube,  or  is  continued  across  the  summit  to 
the  anterior  side,  where  it  opens  out  to  the  exterior  at  —  or  even  beneath  — 
the  arm  bases. 

Infrabasals  five,  elongate,  variable  in  form;  four  of  them,  as  a  rule, 
angular  above  ;  the  posterior  one  broadly  truncate,  supporting  the  first  anal 
plate.  Kadials  decidedly  angular  below.  Costals  two;  ihe  first  generally 
hexagonal.  Distichals  varying  from  two  to  four  in  different  rays,  there  being 
generally  two  in  the  anterior  rays  against  three  or  four  in  the  posterior  ones. 
The  interbrachials,  which  are  numerous  and  of  rather  large  size,  pass  unin- 
terruptedly from  the  dorsal  to  the  ventral  side  of  the  calyx,  and  are  in 
contact  with  the  interambulacrals.  The  first  plate  of  the  regular  sides  rests 
deeply  between  the  sloping  upper  faces  of  two  radials,  its  lower  angle  excep- 
tionally touching  the  basals ;  there  being  two  plates  in  the  second  row,  and 
generally  three  in  the  third.  Anal  side  wider  and  larger  throughout;  the 
first  anal  jdate  placed  upon  the  truncated  basal,  supporting  three  platt  s  ''n 
the  first  row,  and  three  or  more  in  all  succeeding  rows.  The  ventral  surface 
of  the  casts  is  marked  by  well  defined  ridges,  converging  from  the  arm  bases 
to  a  pentangular,  somewhat  elevated  space  behind  the  anus,  the  centre  of 
which  is  represented  by  a  small  cone.  These  converging  ridges  are  open 
grooves  or  galleries  at  the  inner  floor  of  the  disk  for  the  reception  of  subteg- 
minal  ambulacra,  and  the  pentangvdar  space  in  front  of  the  anus  represents 
the  peristome,  of  which  the  mouth  occupies  the  median  part.  Anal  opening 
placed  at  the  distal  end  of  a  tube,  which  is  either  erect  and  passes  outward  at 
the  summit  of  the  disk,  giving  to  the  mouth  an  excentric  position,  or  is  con- 
tinued beneath  the  plates  of  the  disk  to  the  anterior  side  of  the  calyx,  where 
it  opens  out  interradially  or  interdistichally  at  —  or  below  —  the  arm  regions. 
Ventral  disk  covered  with  comparatively  large  plates,  forming  a  sort  of  vault, 
in  which  neither  orals  nor  covering  pieces  can  be  distinguished. 


TIIYSANOCRI     lUM. 


211 


Dhtrthuiiiin.  —  Only  known  from  the  Ni  igara  group    f  Americft. 

Type  of  the  gonna.  —  Siphonocrimta  aniivniiM  (McCht'M.^'v). 

lianurks.  —  TliiH  genus,  by  its  iiHyininctricftl  form,  in  closely  Allied  to 
Lamjikrocriiius,  from  which  it  differs  as  stated  under  that  goinis. 

S.  A.  Miller,  in  proposing  tho  genus,  described  it  as  having  tl  ipo  infr«» 
bnsnls.  We  have  examined  more  than  eighty  specimens,  fiom  tUo  oolliolionn 
of  Mr.  W.  C.  Egan  of  Chicago,  and  Mr.  F.  A,  Greene  of  Milwaukee,  and 
satisfied  ourselves  that  they  all  have  five  plates  in  the  proximal  ring. 

In  studying  the  figures,  it  must  not  bo  overlooked  that  most  of  them 
represent  natural  casts  of  the  internal  surface  of  the  test,  the  plates  theiii- 
selves  having  been  dissolved  by  chemical  action,  and  that  on  these  all  elevti/- 
tions  represent  depressions  of  the  inner  iloor.  Only  in  the  figures  made 
from  casts  in  tho  natural  moulds  does  tho  surface  represent  the  true  external 
surface  of  the  plates. 

SiphonoorlnuB  armosus  O^cChessky). 
Flute  XIX.  Fiqs.  3a,  h,  c. 


1S59. 
1807. 

18S1 
18S2. 
1888. 


Euettlf/ptoerinua  armosus  —  McCiiESNEY ;  Dcscr.  New  Palicoz.  Foss.,  p.  9.5. 

(?)  tf/jf/j/ofmwjflrMaiKs  — McCiiesnky;  Trims,  Acnd.  Sci.  Cliicngo,  p.  23,  Vol.  I.,  Plnte  7,  Figs. 

Art,  b. 
(?)  Gli/plaater  armosus  — Vf.  mid  Sp. ;  Revision  PaliFocr.,  I'nrl  U.,  p.  I'Jfl. 
Gli/iilocrhius  armosus  — ViwnvXY.i.vi;  Gcol.  Surv.  Wis.,  Vol.  IV.,  p.  2SI,  Tlntc  16,  Fig.  11. 
SipAonocrinus  armosus  — S.  A.  Milleu;  Amcr.  Geologist,  Vol.  I.,  p.  H'A. 

Syu.  Glyptoeriiius  siphonatus—\lkU.\  Hep.  of  Progr.,  Geol.  Surv.  Wis.,  p.  22;  mid  20tli  Rep. 
N.  York  Stnto  Cub.  Nat.  Hist.,  Plato  10,  Fig.  11. 

A  large  species,  only  known  from  internal  casts.  Calyx  subovoid.  Dorsal 
cup  generally  higher  than  the  ventral  disk,  its  sides  decidedly  convex,  sub- 
globose  ;  section  across  the  arm  bases  slightly  lobed. 

Infrabasals  small,  forming  a  shallow  cup.  Basals  as  large  as  the  first 
costals,  the  upper  angles  unusually  sharp,  exceptionally  touching  the  inter- 
brachials.  Radials  larger  than  the  costals;  the  first  costals  laiger  than  the 
second,  and  hexagonal.  Distichals  and  palmars  in  series  of  two  each.  Arms 
four  to  the  ray,  their  structure  unknown.  The  plates  of  the  regular  inter- 
brachial  spaces  generally  consist  of  four  rows,  arranged  :  1,  2,  2,  3 ;  tho  first 
plate  as  large  as  the  first  costal.  Anal  interradius  considerably  wider,  greatly 
bulging  from  below  the  arm  bases ;  the  first  anal  higher  than  the  radials, 
succeeded  by  three  plates  in  the  second  and  third  rows,  and  numerous  irre- 
gular, rather  large  plates  at  the  disk.  The  latter  plates  together  form 
a  trumpet-shaped  inflation,  apparently  representing  a  subtegminal  anal  tube^ 


h 


212 


THK  tUINOlDKA  CAMKUATA  OF  NOUTil  AMKUICA. 


wliieli  ciossos  tlio  mouth,  ovoilioH  the  iippcr  pftrt  of  tho  nntcrior  nmbuhicra, 
mill  is  c'outiiuiuil  .Hiibtc'giiiiiiiiUy  all  thu  way  to  the  tintL'rior  nitlc  of  the  calyx, 
ovun  beyond  the  arm  regioiin,  where  it  bemla  outward.  The  anibu!aera,  a« 
Keen  iVoui  iho  converging  ridgcH  upon  the  castH,  vary  coimidurabiy  in  Icngtii 
in  Homo  of  tlio  rays,  tho  posterior  ones  being  much  longer,  especially  those 
to  the  left,  which  are  (|uite  conspicuously  displaced.  Tiiu  excentric  position 
of  thu  mouth,  and  the  irregular  arrangement  ol' tho  ambulacra  of  this  specieM 
remind  us  of  the  Comatulid  genus  Actiimintlra. 

llurlxiiii  (Old  Lvculi/i/.  —  Upper  part  of  Niagara  group  j  Bacine,  Green- 
field und  Waukesha,  Wise,  and  Chicago,  Ills. 

Slphonoorinua  nobllis  (Hall). 
Flute  XIX.  Fiijs.  la,  b,  and  2a,  b,  c. 

1801.     Glyphn-rlttun  mMia  —  Hall  ;  Hip.  I'mgr.  Cicol.  Smviy  Wise,  p.  21 ;  ulso  1907,  80lh  Hep.  N.  Yurk 

suite  Call.  Nut.  Hist,,  I'lnlc  1(1,  Kiffs.  9,  10, 
18S1.     (V)  (ll;/i)t„friiiii!i  Hcihilia  —  Vi .  iiiul  Sp. ;  Ilcvislim  Pnln'ocr,  Port  II.,  p.  ISO. 
\S'ii.     Oli/iiluiriiiHn  uiihili.i —  WiiiTFlKLU:  (icol.  Wisconsin,  V(i|.  IV,,  p.  iiSi,  I'liiti'  10,  I''i){s.  9,  10. 
ISSS.     Sijiliiiiweriiiiiii  iiuljilis  —  8.  A.  Miller;  Aincr.  (Ji'oli)({ist,  Vol.  I.,  No.  5,  Fijf.  2<i5. 

Calyx  as  large  as  in  tho  preceding  species,  and  of  similar  form  ;  but  tho 
ventral  di.sk  pro[)ortionnlly  higher,  and  the  anal  tube  directed  upwards,  not 
being  conducted  subtogminally  to  the  anterior  side  of  the  cidyx.  The  orna- 
menttition  —  as  observed  in  gutta  percha  casts  taken  from  natural  moulds 
in  the  rock  —  is  characterized  l)y  sharp  radiating  ridges,  pas.-^ing  from  the 
centre  of  each  plate  to  adjoining  ones,  and  presenting  upon  the  surface 
of  each  a  well  defined  stellate  figure  with  a  slight  elevation  in  the  centre. 
A  similar  style  of  ornamentation,  but  less  distinct,  occurs  upon  the  plates  of 
the  disk  and  anal  tube. 

Infrabasals  and  basals  as  in  S.  armosus ;  tho  latter  with  sharp  upper 
angles  reaching  far  up  between  the  radials,  and  sometimes  meeting  the  first 
interbrachials.  Costals  smaller  than  the  radials.  Distichals  three,  large ; 
succeeded  by  several  palmars,  which  are  but  little  larger  than  good  sized 
arm  plates.  There  are  four  arm  openings  to  the  ray,  arranged  in  pairs, 
with  a  shallow  depression  between  each  pair,  and  a  somewhat  wider  and 
deeper  one  between  tho  pairs  of  different  rays,  the  latter  extending  quite 
a  distance  into  the  ventral  surface,  and  forming  deep  grooves  along  the 
margin.  Arm  structure  unknown.  Interbrachials:  1,  2,  2,  2,  3 ;  succeeded 
in  the  disk  by  comparatively  large,  less  regularly  arranged  plates,  which 


,  1 


TIIYSAN«KHIMI)^K. 


213 


coniplt'tcly  coviT  mouth  aiul  luiibiiliiom,  aiiimiL-ntly  without  tho  iiMMiHtiiiicd  ol' 
uraU.  Aiiiil  Huli'  gruiitl)'  protruihiig,  forming  lui  immciiHu  projection,  wliich 
hcgiuH  in  the  durmil  cup,  and  uxtundM  to  over  onu  third  of  tht!  wholu  Hur- 
Ciicu  of  thu  dixk,  giving  to  thu  Mpoeimen  an  oxcuudingly  irreguhir  form. 
The  projection  ruMi'inblen  an  inllatod  Mac,  whicli  toward  tiic  upper  end 
grown  decitledly  Mnndier,  and  on  approaching  llie  Huiiimit  turuM  ahrnptly  up- 
wards in  form  of  a  gooil  mzed  tube.  Tiie  (IrMl  anal  plate  rcstn  upon  the 
broadly  trimcated  posterior  basal,  and  \h  followed  by  thrco  jdates  in  the 
Hccond,  and  thrco  or  more  in  tho  succeeding  rows.  IntcrdiMtiihalM  1,  2,  li; 
the  lower  plate  resting  upon  the  upper  sloping  faces  of  the  second  disti(dials. 
The  inflation  upon  tho  disk,  as  appears  from  the  impressions,  was  covered  by 
n  large  numl)er  of  plates  without  definite  arrangement.  There  were  a  few 
large  plates,  surrounded  by  smaller  ones,  all  slightly  convex  and  ornamented 
in  a  similar  manner.  Mouth  oxcentric,  marketl  in  the  casts  by  a  stellate 
protuberance,  from  which  the  ambulacra  pass  out  to  tho  nrm  openings. 
Column  unknown. 

JIurtzon  and  Luculity,  —  Same  as  last. 


r 


Siphonoorinus  pentagonus  w.  and  Sr.  (nov.  spoo,). 

Plate  XIX.  Figs.  4n,  h. 

A  Icrge  species,  of  the  type  of  ^S".  vohlVis.  CaUx  decidedly  asymmetrical, 
about  as  high  as  wide,  strongly  lobed  at  tho  nin  regions;  tho  depressions 
deep  and  wide.  Posterior  side  of  the  calyx  enormously  inlhited  from  the  top 
of  the  anal  plate  to  tho  summit  of  the  disk,  tho  bulging  involving  the  left 
posterior  ray,  which  projects  more  conspicuously  than  the  others.  Dorsal 
cup  obconical,  the  sides  evenly  sjircading  to  the  top  of  the  costals,  thence 
more  rapidly  to  the  arms.  The  upper  angles  of  the  basals  and  lower  angles 
of  the  interbrachials  more  obtuse  than  in  the  preceding  species,  and  never 
in  contact.  Radials,  costals,  and  interbrachials  of  nearly  uniform  size ;  the 
first  costal  somewhat  larger  than  the  second.  The  first  distichal  as  large  as 
the  upper  costal,  the  two  following  considerably  smaller,  the  succeeding  ones 
free  arm  plates.  Arm  structure  unknown.  Interbrachials  1,  2,  3,  followed 
by  interambulacrals.  The  nnul  plate  is  succeeded  by  three  and  four  plates, 
the  latter  supporting  the  plates  of  the  anal  protuberance,  which  on  approach- 
ing the  top  of  the  disk  contracts  rapidly,  and  turning  abruptly  upward,  forms 
a  tube  at  the  summit.      Ventral  disk  one  fourth  shorter  than  the  dorsal 


214 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


cup;  the  moatb  quite  excentvic,  and  the  posterior  ambulacra  considerably 
longer. 

.Uorizon  and  Locality.  —  Same  as  last. 

Ti/jye  in  the  collection  of  W.  and  Sp. 

Rtmwks.  —  Th\i  species  is  readily  distinguished  from  the  preceding 
species  by  having  but  two  arms  to  the  ray  from  the  calyx,  which,  however, 
may  branch  in  their  free  state. 


RHODOCRINIDiE  Roe^her  (1855). 

DiCYCLIC.  LOWEU  BRACHIALS  AND  INTEBBRACIIIALS  FOBMING  AN  IMPOniANT  PART  OP 
THE  DORSAL  CUP.  RaDIALS  SEPARATED  ALL  AROUND  BY  AN  INTERRADIAL  PLATE 
WHICH   IS    FOLLOWED   BY   WELL-DEFINED,    REGULARLY   ARRANGED   INTERBRACUIALS. 

Analysis  of  the  Genera. 

Infrabasals  5.    Basals  5. 

A.  Anal  intekradius  oknerally  with  additional  plates. 

1.  Arms  uhiserial. 

a.     Arms  not  branvhing. 

Basals  oxposcd  in  a  side  view Ehaphanocrinus- 

2.  Arms  hiserlal. 

a.  Arms  hranchhKj. 

Calyx  obovate  •  anus  without  a  tube ;  interbrachials 
numerous,  two  in  second  row ;  interdistichals  gen- 
erally present Arch^ocrinus. 

Calyx  depressed  globular,  anus  at  end  of  a  tube,  first 
interradials  frequently  separated  from  basals  by 
supplementary  pieces.  No  interdistichals.  Arms 
probably  given  off  from  brachial  prolongations  of 

the  calyx Diadolocrinus. 

Calyx  globose,  flattened  or  concave  below  ;  two  or  three 
interbrachials  in  second  and  succeeding  rows ;  no 
interdistichals. 

Ventral  disk  narrower  than  dorsal  cup  .     .     ,        Ehodocrinus. 
Ventral  disk  equal  to,  or  exceeding  dorsal  cup ; 
tubular  appendages  suspended  from  mar- 
gin of  disk Gilbertsocrinus. 

b.  Arms  not  branching. 

Calyx  globose,  arms  long  and  heavy ;    interdistichals 

numerous TnYLAcocRiNUs. 

B.  Anal  interradius  without  additional  plates. 
1.     Arms  biscriol. 

a.  Arms  not  brnnchinfj,  dorsal  cup  broadly  truncate  at  the  bot- 

tom, radials  sometimes  not  all  separated;  arm  facets 

directed  upward Lvriocrinis. 

b.  Arms  branching. 

One  costal ;  interdistichals  few Antiiejiocrinus. 

Two  costals ;  rays  produced  into  long  trunks  giving  off 

armlets  from  opposite  sides Eipidocrincs. 

C.  Anal  interradius  unknown. 

Arms  uuiserial,  branching  frequently ;  infrabasals  very  small  .    Diamenocrinus. 


y\ 


W  -i\ 


\ 


216  THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 

Geological  (mil  Geo(jraj)hical  Distribution, 

Number  of  known  species. 

(Open  figures  indicate  Anicrieau,  those  iimiked  ( ),  European.) 


Formation. 

Khodochiniu.e. 

C 

o 

« 

s 

E 

1 
1 

1 
g 

_s 

American. 

1      ^ 

■<ww 

o 

g 

CO 

3 

"E 

< 

3 

a 

■c 

§ 
1 

g 

o 

s 
•E 
§ 

Eh 

o 

J 
"P. 

H 

3 
C 

•c 

o 

.s 

§ 

a 

ID 

M 

a 

.s 

o 

3 
u 

§ 

c 

5 

Keokuk. 

If 
^5 

3 

2 

Upper  Burlington. 

3 

0"') 

3 

(4) 

Lower  Burlington. 

^ ,  ^ 

Kinderliook. 

3    1 

Hamilton. 

Up.  Devon. 

1 

(2) 

1 

1 

_(2)_ 

(1) 

(1) 

Upper  Ilelderberg. 

Eifel  bed. 

Niagara. 

Wenlock. 
Gotland. 

•* 

(2) 

Hudson  Itivcr. 

1 

Trenton. 

1 
2 

4 
4 

2 
2 

10 

(4) 

Total  species  34  |  '.L 

1 
(2) 

2 
(1) 

(2) 

(1) 

(1) 

licmarks.  —  When  Roemer  established  the  Rhodocrinida},  he  was  ac- 
quainted only  with  the  genus  Rliodocrinus,  in  which  he  included  also  the 
sjiecics  which  were  afterwards  referred  to  Rlpidocriims  and  Gllhertsorrinm. 
He  omitted  Acaiithocrimis,  which  he  had  himself  proposed  in  1850,  probable- 
having  discovered  its  identity  with  Bhodocrinm. 

The  earlier  French  writers,  d'Orbigny,  de  Koninck,  Pictet,  and  Diijardin 
and  Ilupd,  placed  Ithodocrhms  with  the  Cyatliocrinidoo. 

The  Rhodocrinida?  of  Zittel  and  de  Loriol  embrace  Rliodocrimts,  OU/i- 
crinus,  Acanthocrhnis,  Ripklocrinm,  Iladrocnmis,  Tri/hliocrhms,*  and  Thi/sano- 

•  Wo  Imvc  not  seen  Geinitz's  description,  but  judge  from  Zittel  (llandb.  der  Palieont.,  Vol.  I.,  p.  377) 
that  it  is  a  do\ibtful  ur  imperfectly  defined  genus. 


RHOUOCRINID^, 


217 


criniis.  S  A.  Miller  in  1889  added  Lyriocrinus,  and  adopted  Lyon's  name 
Gotiiasteroidocrimts  in  place  of  OUucriinis.  He  amended  this  in  the  following 
year  by  leaving  out  the  monocyclic  Iladrocnniis,  and  adding  Arcliwocrbms 
and  Raplumocrituis. 

To  the  genera  which  we  arranged  under  this  family  in  1885,*  we  add  the 
genus  Dlaholocrlnm,  which  we  have  proposed  for  a  species  that  had  been 
previously  referred  by  us  to  Arclueocrinus. 

The  Rhodocrinida3  are  nearest  related  to  the  Thysanocrinida;,  but  are 
readily  distinguished  by  the  complete  lateral  separation  of  the  radialsf  by 
the  interradials  ;  the  radials  of  the  ThysanocrinidoD  being  in  lateral  contact 
except  at  the  anal  side.  The  marked  asymmetry  in  the  ventral  disk,  so 
characteristic  of  the  latter  family,  is  not  ob- 
servable in  the  Rhodocrinida?,  in  which  the 
whole  calyx,  as  a  general  rule,  is  remarktably 
symmetrical. 

The  family  has  a  great  stratigraphic  range, 
extending  from  the  Lower  Silurian  to  the 
middle  of  the  Carboniferous  and  becoming 
extinct  in  the  Keokuk  group.  The  ancestral 
type  is  probably  Archwoerinus  in  the  Trenton 
group,  of  which  Diuholocrimts  is  an  offshoot. 
The  evolution  of  these  forms  through  Lyrio- 
rrbius  in  the  Niagara,  lliylacocrinus  and  R'qn^ 
(locrinus  in  the    Devonian,  to  the   profusely 

developed  Rhodoci-lnus  in  the  Carboniferous,  is  by  easy  gradations.  Nor 
is  the  step  from  Bhodocriiw^  to  the  highly  specialized  Gllhertsocrimis  a 
difucult  one,  because  there  are  transition  forms  in  which  the  characters  of 
the  two  genera  are  to  a  great  extent  merged.  Raphanocriinis  in  the  Trenton, 
and  Anthemocriniis  from  the  Upper  Silurian  of  Gotland,  apparently  repre- 
sent variations  toward  the  Thysanocrinida). 

The  Rhodocrinidae  are  by  far  the  most  important  dicyclic  family  of  the 
C.amerata,  being  composed  of  ten  genera  and  fifty-four  species,  of  which 
thirty-six  are  from  America,  and  eighteen  from  Europe. 

•  Revision,  Part  II.,  pp.  96  to  99.    (Proceed.  Acad.  Nat.  Sci.  Pliila.,  pp.  318-321.) 
•)■  There,  is  an  occasional  exception  to  this  in  the  genus  Lyriocrinm,  wlierc  tlie  rndinls  arc  sometimes 
connected  by  a  narrow  strip,  except  at  the  anal  side.    This  occurs  (piile  frequently  in  L.  iliwli/lm  from  tlie 
Niiij^iira  of  New  York ;  while  in  L.  melissa,  L.jiivenis,  and  an  undcscribed  Li/riocriiius  from  Dudley,  England, 
the  radials  are  widely  separated. 

28 


Fig.  10 — Rhodocrinus. 


^1 


i  M 


gB?jmBL— ■J'LSJW^BWWfwegBBgMgi' 


218 


TIIK  CRINOIDKA  CAMP:RATA  OF  NOHTII  AMKKICA. 


I  '  I 


In  the  ilcscriptions  of  the  RliodocrinicloD,  tlie.  plnte  which  is  interposed 
between  tlie  radials  is  called  tlu*  first  inteiradial  as  a  matter  of  convenience, 
and  those  following  it  in  the  dorsal  cup  interbrachials,  although,  as  elsewhere 
explained,  they  all  belong  undoubtedly  to  the  same  system  of  plates. 


RHODOCRINUS  Miller. 

1821.  Miller  (in  pnrt) ;  Nut.  Hist,  of  the  Criiioidcn,  p.  lOfi. 

1S35.  Agassi/.;  Mem.  Hoc.  Sci.  Ncucliiil.,  Vol.  I.,  p.  196. 

1841.  MCller  (in  iiail);  Moimtsber.  <i.  llcrliii.  Aknd.,  p.  209. 

1S43.  Austin;  Ann.  unci  .Mag.  Nut.  Hist.,  Vol.  X.,  p.  109. 

1830.  D'Orhigny;  Proilr.  do  Paleont.,  Vol.  I.,  ji.  104. 

1S33.  Dr.  KoNlxcK  nnd  Lk  Hon  (in  pnrt);  Uoclipr.  Grin.  Carb.  Bclg.,  p.  103. 

1853.  lloKMER  (in  part);  Loth.  Gcogn.  (Ansg.  3),  p.  240. 

1855.  (?)  MCi.LER  (Wirtgcn  nnd  Zcilci);  Vcrli.  Nntnrliist.  Vcrcin  f.  Rliciiil.,  Vol.  XII.,  p.  11. 

1857.  I'icTET;  Tiaile  do  l'al6ontologio,  Vol.  IV.,  p.  314. 

1858.  ll.KU.;  Gcol.  Hep.  Iowa,  Vol.  I.,  I'aH  II.,  p.  550. 
1861.  Hall;  Host.  Jonrn.  Nat.  Hist.,  Vol,  VII.,  p.  322. 

1868.     Meek  and  Woktiien  ;  fiool.  ]{pp.  Illinois,  Vol.  III.,  p.  476. 

l'>75.     Grenfeli.  ;  Proceed.  Bristol  Naturalists'  Soc,  Vol.  I.,  Part  III.,  p.  480. 

1879.     Zittel;  llandb.  d.  Pnln-ontologic,  Vol.  I.,  p.  376. 

1881.     W.  and  Sr.;  Kovision  Paliener ,  Part  II.,  p.  209  ^Proceed.  Acad.  Nat.  Sci.  Pliila.,  p.  383). 

1883.     WoRTllKx;  Gcol.  Kcp.  Illinois,  Vol.  Vll.,  p.  303. 

1883.     Quexsteut  (in  ]iarl)  ;  Handb.  d.  Potrefactonknndc  (Ausg.  3),  p.  958. 

1889.     W.  and  Sp. ;  Gcol.  Rep.  Illinois,  V<d.  VIII.,  p.  180. 

1889.     S.  A.  Miller;  N.  Amor.  Gcol.  and  Palicont.,  p.  277  (not  Fig.  417). 

(Not  KhoiloerhiH.i  Golilf.,  1826,  Petrel".  Gennaniie,  A'ol.  I.,  p.  212;  nor  McCoy,  1844,  Cnrbonif. 

Foss.  Ireland,  p.  ISO;   nor  V.  Roomer,  1S51,  Verb.  Natnrli.  Vcrcin  f.  Rheinl.,  Vol.  VIII., 

p.  358;  nor  Billings,  1859,  Geol.  Rep.  Canada,  Decade  IV.,  p.  61;  nor  Lyon,  1861,  Proc. 

Acad.  Nat.  Sci.  Pliiia.,  p.  409 ;  nor  Hall,  ISfiS,  Trans.  Albany  Inst.,  Vol.  IV.,  p.  198,  and  1876, 

1st  edit,  of  2Sfb  Rep.  N.  Y.  State  Mus.  Nat.  Hist.,  p.  139;  nor  SchuUy.c,  1867,  Mon.  Eeliin. 

Fill.  Kalkcs  p.  53;  nor  White,  1880,  Proc.  United  States  National  Mns.,  p.  259.) 
Syn.  Acanthorriiim  F.  Roemer,  1S50.     Nencs  Jalirb.  f.  Min-^ralogie,  p.  79 ;  Miillcr,  1853,  Vcr 

bandl.  Naturb.  Verein,  Vol.  XII.,  p.  8;   Hall,  1862  (Subgenus  of  Rhoihcrinus),  15tb  Rep. 

N.  Y.  State  Cab.  Nat.  Hist.,  p.  125. 

Calyx  more  or  less  globose,  the  dorsal  cup  generally  somewhat  flattened 
r  concave  at  the  base,  and  constricted  in  the  upper  part.  Plates  flat  or 
convex,  nodose  or  spiniferous,  their  surfaces  smooth  or  striated.  Infrabasals 
five,  smnll,  sometimes  merely  occupying  the  bottom  of  the  colunmar  con- 
cavity. Basals  five,  large,  all  truncated  at  the  upper  end.  E^tdials,  as  a  rule, 
larger  than  the  costals,  but  smaller  than  the  basals.  Costals  two,  not  unfre- 
quently  coalesced,  so  as  to  form  practically  a  single  plate,  Distichals  free  in 
part ;  rarely  more  than  one,  and  never  exceeding  three,  take  part  in  the 
calyx.  Arms  arranged  in  pairs  and  bifurcating;  biserial,  either  directly  from 
the  calyx  up,  or  from  the  last  bifurcation  ;  joints  short ;  the  pinnules  in 
contact.     The  first  interradial  plate  is  followed  by  several  rows  of  inter- 


im 


I'!    H 


i* 


RIIODOCRIXIIXE. 


219 


bracliials,  the  second  row  consisting  eitlier  of  two  or  three  pieces.  When 
there  are  two  plates  at  the  reguhir  sides,  tiie  anal  side  has  always  throe,  but 
when  the  former  has  three,  there  is  no  additional  plate  at  the  anal  side. 
Ventral  disk  narrow,  rising  but  little  above  the  dorsal  cup ;  composed  of 
irregulorly  arranged  plates,  none  of  which  can  bo  recognized  as  orals.  Disk 
ambulacra  subtegminal.  Anus  excentric,  sometimes  marginal.  Column 
round;  the  axial  canal  pentagonal  or  stelliform;  the  internodes  frequently 
consisting  of  but  one  joint. 

Distribution. — Ehodocrinus  first  appears  in  America  in  the  Hamilton 
group ;  it  attains  its  climax  in  the  Kinderhook  and  Burlington  beds,  and 
becomes  extinct  at  the  end  of  the  Keokuk  epoch.  Specimens,  as  a  rule,  are 
rare.  In  Europe  the  genus  occurs  in  the  Jl/ieinisch  Ueherijanrjsfjchinjc,  and  it 
is  represented  by  several  species  in  the  Mountain  limestone. 

Type  of  the  genus :  Ehodocrinus  vents  Miller,  from  the  Carboniferous  of 
England. 

Bemarks.  —  Rhodocrinus  verus,  according  to  J.  S.  Miller,  occurs  in  the 
Mountain  limestone  of  Yorkshire,  and  also  in  the  Wenlock  limestone  of 
Dudley,  England,  and  it  was  said  to  have  three  basal  ])lates.  Miller  con- 
founded two  very  different  types,  which  have  since  been  recognized  as 
distinct  genera.  Tiie  Carboniferous  form,  which  took  Miller's  specific  name, 
is  universally  regarded  as  the  type  of  the  genus  Jihodocrinus,  having  five 
infrabasr.ls  instead  of  three,  and  biserial  arms ;  the  Silurian  form  from  Dud- 
ley, with  three  infrabasals  and  single  arm  joints,  was  described  by  Phillips  as 
Sagenocrimts  expansus. 

The  genus  lihodocriniis,  as  we  understand  it,  includes  species  with  smooth, 
nodose,  and  spiniferous  plates.  For  a  certain  species  with  spinous  plates 
from  the  Devonian,  Roemer  proposed  the  genus  Acaiithocrinus.  We  have 
carefully  examined  the  figures  of  A.  longispinus,  as  given  by  Wirtgen  and 
Zeiler,*  but  have  failed  to  discover  any  characters  by  which  this  form  can 
be  separated  even  subgenerically.  Spinous  projections  on  the  basals  and 
radials  occur  quite  frequently  also  among  Carboniferous  species  in  all  possible 
variations.  It  is  possible  that  "  Rhodocrinus  gonatodes  "  Midler  belongs  to 
Oehlert's  new  genus  Diamenocrinus. 

We  have  referred  Rhodoerinus  microbasiUs  and  R.  pyriformis,  both  of 
Billings,  to  Archwocrinus ;  R.  vesiKralis  White  to  Diabolocrinus ;  R.  melissa 
Hall  to  Li/riocrinus ;  R.  Hcdli  Lyon  to  Thi/sanocrinus ;  R.  stcllaris  de  Koninck 

•  Verb.  d.  Naturbist.  Vcrein,  Jabrg.  XII.,  Tab.  II. 


?l 


220 


THE  C'KIXOIDEA  CAMEKATA  OF  NORTH  AMERICA. 


and  Le  Hon  to  GUbertsocrinvs.  Tlie  following  species  are  too  little  known  to 
be  recognized :  li.  spinosm  Hall,  li,  (jradlis  Hall,  R.  varsoviensis  Hall,  and 
It.  rectus  Hall. 

RhodocrinuB  Wortheni  Hall. 
Plate  XL  Fig.  G,  and  Plate  XII.  Figs.  7a,  b,  c. 

1858     IUli-;  Gcol.  Rep.  Town,  Vol.  I.,  Part  II.,  p.  556,  Plato  9,  Figs.  8a,  b,  e. 
18S1.    W.  mid  Sp.  j  Ilevisioii  Pulteocr.,  Part  II.,  p.  213. 

A  small  species.  Calyx  depressed-globose,  a  littlo  concave  at  the  bottom; 
plates  delicate,  flat  and  perfectly  smooth.  Infrabasals  of  moderate  size,  the 
tips  slightly  projecting  beyond  the  column ;  forming  a  pentagon.  Basals  very 
large,  a  littlo  wider  than  long.  Radials  nearly  as  large  as  the  basals,  angular 
below,  narrowly  truncated  above ;  their  lateral  faces  parallel.  Costals  two, 
generally  anchylosed,  the  two  together  smaller  than  the  radials,  and  only 
half  their  widtii ;  the  first  quadrangular.  Distichals  2  X  10  in  the  calyx, 
those  of  the  lower  row  nearly  as  large  as  the  costals,  the  upper  smaller,  and 
excavated  to  form  the  arm  bases,  which  do  not  project.  Ambulacral  open- 
ings small,  slitlike,  directed  upwards,  and  arranged  in  pairs  around  the  disk. 
Arms  delicate  and  cylindrical ;  they  branch  twice  above  the  calyx,  and  are 
nniserial  to  the  first  bifurcation,  then  turning  into  biserial,  with  short  inter- 
locking pieces.  The  five  plates  interposed  between  the  radials  are  consider- 
ably smaller  than  the  basals,  and  but  littlo  larger  than  the  two  succeeding 
interbrachial.s,  which  are  followed  by  two  rows  of  two  .small  plates.  At  the 
anal  side,  the  first  interradial  plate  is  larger  than  those  of  the  regular 
sides,  and  followed  by  three  plates.  Ventral  disk  very  small,  and  following 
the  general  curvature  of  the  calyx.  Column  small,  round  ;  the  upper  joints 
rounded  at  their  edges ;  the  axial  canal  minute. 

Horizon  and  Loca/if;/.  —  Lower  Burlington  limestone,  Burlington,  Iowa. 

Ti/pe  in  the  Illinois  State  collection,  Springfield. 

Remarks.  —  Specimens  apparently  of  this  species,  are  found  in  the 
Waverly  group  of  Cuyahoga  Co.,  0.,  as  natural  moulds ;  the  caly.x,  however, 
appears  to  be  more  depressed,  and  larger  in  proportion  to  the  length  of  the 
arms.  Similar  specimens,  but  decidedly  more  urn-shnped,  occur  in  the 
Burlington  beds  of  Lake  Valley,  New  Mex.,  for  which  we  propose  the  name 
Rhodncrimis  Wortheni,  var.  iirceolatus  (PI.  XII.  Figs.  8,  6).  The  typical  form 
resembles  R.  ivatersianus  W.  and  Sp.,  and  R.  Wachsmuthi  Hall ;  from  which 


4     r 

m 


RIIODOCRlNIDiE. 


221 


it  differs  in  the  mode  of  branching  of  the  arms,  and  the  fact  that  the  latter 
has  convex  calyx  plates;  also  in  its  basal  concavity  being  much  deeper, 
the  column  larger,  and  calyx  higher. 

Rhodooriiius  Wortheni,  var.  uroeolatus  W.  and  Sp. 
Plate  XII.  Figs.  8a,  b. 

Differing  from  the  typical  form  of  E.  Wortheni  in  the  form  of  the  calyx, 
which  is  urn-shaped  instead  of  globular,  higher  than  wide  and  rounded  at 
the  bottom,  while  that  is  flattened.  The  infrabasals  are  convex,  and  on 
a  level  with  the  basals.  The  greatest  width  of  the  calyx  is  across  the  first 
costals,  whence  it  contracts  rapidly  to  near  the  arm  bases,  which  slightly 
project  outward,  giving  to  the  tegmen  a  decidedly  pentangular  outline. 
Ventral  disk  almost  flat,  wider  than  in  the  typical  form,  and  the  plates  less 
numerous.  Anus  subcentral,  and  not  protuberant.  The  plates  of  the  calyx 
flat  and  without  ornamentation. 

Horizon  and  Locality.  —  Age  of  the  Lower  Burlington  limestone,  Lake 
Valley,  New  Mexico. 

Types  in  the  collection  of  Wachsmuth  and  Springer. 

Rhodoorinus  watersianus  w.  and  Sp. 
Plate  XII.  Fig.  9. 

1889.    W.  and  Sp.  ;  Geol.  Rep.  Illinois,  Vol.  VIII.,  p.  184,  Plnte  17,  Fig.  16. 

A  small  species  ot  the  type  of  Rhodocrinus  Wortheni,  from  which  it  differs 
in  the  more  concave  base,  the  proportionally  smaller  size  of  the  basals,  in  the 
more  elongate  form  of  the  calyx,  and  in  the  arm  structure.  Calyx  from 
sub-globo.se  to  sub-ovoid,  truncate  at  the  bottom  and  narrowly  concave  ; 
plates  very  slightly  convex,  and  without  ornamentation. 

Infrabasals  small  and  concealed  by  the  column.  Basals  moderately  large, 
their  lower  ends  abruptly  deflected  inward,  their  upper  portions  curving  out- 
ward and  upward.  Radials  somewhat  smaller  than  the  basals;  as  wide  as 
long.  Only  the  proximal  distichals  take  part  in  the  calyx  ;  they  are  followed 
by  five  to  six  slightly  cuneate  free  plates,  of  which  the  upper  one  is  axillary, 
and  supports  two  arms,  which  remain  simple.  Arms  twenty,  rounded  on  the 
back,  slender,  very  little  tapering,  and  biserial  from  the  last  bifurcation  ;  the 
joints  moderately  high  and  a  little  convex.  Pinnules  stout  for  the  genus. 
The  first  interradial  plate  as  large  as  the  radials ;  followed  by  five  to  six 


^1 


i\ 


222 


THE  CRINOIDEA   CAMERATA  OF  NORTH  AMERICA. 


interbrachials  in  two  or  tliree  rows.  Tlie  nnal  side  lias  tlie  same  number  of 
Interbrachiul.x,  but  thoHO  enclose  a  longitudinal  row  of  three  ratlier  large  anal 
plates.  Ventral  disk  small,  somewhat  receding  from  the  dorsal  cup,  produc- 
ing nn  offset  or  groove  around  the  margin  ;  it  is  convex,  and  composed  of 
small  irregular  plates.  Column  circular;  the  joints  rounded  at  the  edges; 
the  nodal  joints  a  little  wider  and  higher.  The  internodes  at  about  three 
inches  from  the  calyx  consist  of  six  pieces,  and  the  same  number  apparently 
persists  throughout  the  rest  of  the  colunui.  Like  most  of  these  stems,  it 
tapers  considerably  downward,  and  near  the  distal  end  is  provided  with  com- 
paratively stout  cirri  or  rootlets,  irregularly  given  off  from  the  sides. 

Horizon  and  LocaVitij.  —  Kinderhook  group,  Le  Grand,  Marshall  Co.,  lown. 

Ti/pcs  in  the  collection  of  Wachsmuth  and  Springer. 

Bhodocrinus  ooxanus  Woktden. 
Plate  XIII.  Figs.  6  and  7. 

1883.    Wortiikn;  Gcol.  Kcp.  Illinois,  Vol.  VII.,  p.  305,  Plate  28,  Fig.  7. 
1385.     W.  and  Sr. ;  Kcvision  riiUeocr.,  Part  III,,  p.  99. 

Syn.  Rhoiloeriiius  poli/ildclglm  Wohtiien;  18S3,  Gcol.  Kcp.  Illinois,  Vol.  All.,  Plate  27,  Fig.  5. 

The  two  specimens  figured  by  Worthen  as  Ithodocrinns  coxanus  and 
li.  2)oli/dactyhis  are  too  much  crushed  and  distorted  to  admit  of  critical  com- 
parison or  satisfactory  description.  Both  appear  to  have  smooth  plates,  and 
the.se,  so  far  as  we  can  ascertain,  are  arranged  substantially  in  the  same 
way ;  but  R.  ])ohjdaci>/hi,%  according  to  Worthen's  figure,  has  an  additional 
bifurcation  in  one  of  the  ray  divisions,  i.  e,  five  arms  to  the  ray.  Whether 
this  is  a  persistent  character  cannot  be  ascertained  from  the  specimens, 
and  until  this  is  proved  we  prefer  to  regard  i?.  2>ohidactylus  a  synonym  of 
E.  co.ranus. 

Horizon  and  Locality.  —  Upper  part  of  the  Geode  bed  in  the  Keokuk 
group  ;  Hamilton,  Ills. 

Types  in  the  collection  of  L.  A.  Cox  of  Keokuk. 

Bhodocrinus  Wachsmutbi  Hall. 
Plate  XIII.  Figs  5a,  h,  c,  d,  and  Plate  XV.  Fig.  7. 

1861.     Ham,;  Piclini.  Dcser.  of  New  Spec,  of  Crinoidea,  Ail)any,  p.  18. 
1881.     W.  and  Sp.;  Uevision  Paloeocr.,  Pt.  II.,  p.  213. 

Somewhat  larger  than  the  three  preceding  species.  Calyx  snbovoid, 
flattened  at  both  poles,  the  proximal  end  abruptly  and  deeply  impressed. 


RIIODOCRINID.E. 


228 


forming  a  circular  pit,  which  is  but  partly  filled  by  the  upper  joint  of  the 
column.  PlatcH  without  ornamentation,  a  little  convex,  the  suture  lines 
slightly  grooved. 

Infrabasals  small,  concealed  by  the  column.  Basnls  as  large,  or  even 
larger  than  the  radials,  their  lower  ends  bending  abruptly  inward  to  take 
part  in  the  pit,  the  upper  portions  curving  gently  outward  and  upward. 
Radials  heptagonal,  a  little  wider  than  long,  and  twice  as  large  as  the 
costals,  which  are  (luite  narrow.  Distichals  free  from  the  first  up  ;  the 
upper  faces  of  the  latter  slightly  excavated  to  form  the  ambulacral  opening. 
The  free  distichals  consist  of  about  eight  plates,  which  are  very  short;  the 
upper  one  axillary,  supporting  two  arms,  of  which  one  branches  again  on 
the  eighth  joint,  while  the  other  remains  simple.  Arms  cylindrical,  of  nearly 
uniform  size,  biserial  al)0ve  the  last  bifurcation ;  the  plates  very  short  and 
transversely  arranged.  Pinnules  rather  stout  and  in  contact ;  the  joints 
twice  as  long  as  wide,  with  deep  ambulacral  grooves.  Interradial  areas  not 
depressed ;  arranged  :  1,  2,  3,  2,  succeeded  by  three  or  four  more  pieces. 
The  anal  side  has  three  plates  in  the  second  row.  Ventral  disk  composed  of 
but  few  plates ;  it  is  .somewhat  elevated  nt  the  margin,  almost  flat  in  the 
middle.  Orals  well  defined  ;  surrounded  by  two  rows  of  rather  large  inter- 
ambulacral  pieces,  which  meet  with  the  interbrachials.  Anus  subcentral, 
opening  through  the  disk.     Column  round  ;  axial  canal  small  and  stellate. 

Horizon  anil  Locality/.  —  Lower  Burlington  limestone,  Burlington,  Iowa. 

Tyj)e  in  the  Museum  of  Comparative  Zoology,  Cambridge. 


m 


'/ 


Rhodoorinus  Whitei  Hali,. 
Tlate  XIII.  Figs,  la,  6,  c,  and  Plate  XV.  Fiys.  6a,  b. 

1861.    Hall  ;  Description  of  New  Spec.  Criiioids,  p.  9. 

1861.     Hall;  Host.  Journ.  Nat.  Hist.,  Vol.  A'll.,  p.  324. 

1872.     Hall;  N.  Y.  State  Mas.  Nnt.  Hist.,  Bull.  I.,  Plate  6,  Tigs.  19,  20,  21. 

1881.     \V.  ami  Sp.  ;  Revision  Palreocr.,  Part  II.,  p.  21.3. 

Syn.  Rhodocrinm  ll'liilei,  vnr.  biirliiifftoiicnsu  Hall  ;  1861,  Bost.  Journ.  Nat.  Hist.,  Vol.  VII.,  p.  32.5. 

The  largest  known  American  species.  Calyx  depressed  sub-globose,  a 
little  wider  than  high  ;  the  lower  portion  flattened  and  formed  into  a  deep 
concavity  ;  the  sides  decidedly  bulging  to  the  first  costals,  then  contracting 
to  near  the  arm  bases.  All  plates  of  the  dorsal  cup  to  the  top  of  the  cos- 
tals of  nearly  the  same  size,  all  strongly  convex,  and  without  ornamentation. 

Infrabasals  of  medium  size,  slightly  projecting  beyond  the  column.     Bas- 


224 


THE  CIUNOIDEA  CAMEEATA  OF  NUKTII  AMEUICA. 


Ills  large,  lying  aliiiOHt  liorizontiiUy,  except  their  proximal  endH,  wliicli  bend 
abruptly  inwartl  luul  take  part  in  tlie  concavity  ;  the  upper  facen  broadly 
truncated.  Radials  liexiigonal,  about  as  wide  as  long.  CoMtals  aH  long  as  the 
rrtdialx,  but  generally  a  little  narrower.  DisticlialH  generally  repreMcnted  by 
only  one  row  of  plates  in  the  calyx,  which  are  excavated  at  the  upper  faces 
to  Ibnn  the  arm  openings,  of  which  tiiere  are  two  to  the  ray.  Nothing  is 
known  of  the  arm  ■itructure.  The  interradial  spaces  are  occupied  by  1,  2, 
3,  and  two  large  plates,  followed  by  two  or  three  sniallcr  ones.  The 
anal  interradius  has  a  lew  more  plates  in  the  upper  rows.  Ventral  disk 
small,  slightl}'  convex,  pentangular  in  outline,  and  composed  throughout  of 
small,  irregular,  slightly  convex  pieces,  which  increase  in  size  as  they  ap- 
proach the  arm  regions.  Anus  subcentral,  at  the  end  of  a  short  tube  or 
elongate  protuberance,  which  gives  to  the  disk  an  irregularly  conical  form. 
Column  small,  not  filling  the  basal  concavity;  it  is  round,  and  there  is  an 
alternation  of  larger  and  smaller  plates.  Axiiil  canal  of  medium  size  and 
stelliform. 

Ilorhon  und  Locality.  —  Lower  part  of  the  Lower  Burlington  limestone, 
Burlington,  Iowa. 

Types  in  the  University  Museum  at  Ann  Arbor. 

Remarks.  —  We  have  examined  a  number  of  specimens  of  this  rare 
species,  including  the  types,  and  are  of  the  opinion  that  the  specimen 
which  Hall  described  as  var.  hurVinfjtimensls  is  a  very  large  example  of 
R.  Wliltei.  That  it  has  one  or  two  additional  interbrachials,  that  the 
calyx  is  proportionally  a  little  shorter  and  the  basal  concavity  deeper,  is 
readily  explained  by  extravagant  growth.  The  species  occurs  in  the  low- 
est layers  of  the  Lower  Burlington  limestone,  and  the  calyx  sometimes 
attains  a  size  of  two  inches  in  diameter. 


Rhodocrinus  Benedioti  s.  A.  Miller. 

1892.     Advance  Sheets  Eighteenth  Rep.  Geol.  Survey  Indiana  bj  Gorby,  p.  15. 

Calyx  small  and  globular,  except  the  tejijmen,  which  is  slightly  conical. 
Dorsal  cup  nearly  as  high  as  wide,  widest  at  the  middle ;  the  sides  evenly 
rounded  to  the  arm  bases  ;  the  base  concave.  Plates  convex,  some  of  them 
angular,  and  the  principal  ones  covered  with  radiating  ridges.  Suture  lines 
distinct. 

Infrabasals  .small,  forming  a  flat  pentagonal  disk.  Basals  the  largest 
plates  of  the  calyx,  highly  convex  in  the  central  part,  with  ridges  extending 


HlIOUOCiUNlU.E. 


225 


to  adjoininjj  plates.  Hiuliiils  nearly  as  larj^o  as  the  basals,  but  the  ritlj^es  less 
conspicuous.  First  costais  smaller  tiiun  the  second,  convex ;  the  second  as 
largo  a.s  tho  lirst.  'I'hc  second  distichals  support  the  free  arms,  which  are 
not  preserved.  Interradiiil  areas  not  depressed  below  the  level  of  adjoining 
brachials  ;  composed  of  the  intcrradial  plate,  and  about  nine  interbrachials, 
of  which  tho  upper  ones  are  very  small.  The  anal  area  has  one  or  two 
additioiud  plates.  Ventral  disk  small ;  its  diameter  scarcely  two  thirds  the 
width  of  the  dorsal  cup  at  the  widest  part;  composed  of  numerous  very 
small,  highly  convex  plates.     Anus  subccntral.     Column  round. 

Horizon  and  Locullhj.  —  Keokuk  group  ;  Harrison  Co.,  Indiana. 

liemurlcH.  —  We  did  not  have  access  to  tho  specimens  to  illustrate  this 
species,  and  were  obliged  to  make  our  description  after  Miller. 


?i 


RhodoorinuB  nodulosus  Hall. 
Plate  XIII.  Fi(j.  S. 

1802.     RMnmiiii.' (.■Ii-rii/fhrriiiii>)  iio(/iilo.iii.H  —  IIali.;   ]5I1i  Itrp.  N.  Y.  Stntc  Cab.  Nnt.  Hist.,  p.  120; 

il)iil.,  1872,  Hull.  I.,  rialc  In,  Vlfi.  8. 
1881.     Rhodocrinm  iiodiitumia  —  W.  ftiij  Si". ;   Uevi.'.ioii  I'nlieocr.,  Part  II.,  p.  212. 

Of  medium  size.  Dorsal  cup  more  rapidly  .spreading  to  tho  top  of  the 
second  costais  than  from  there  to  the  arm  bases  ;  height  and  greatest  width 
about  equal;  interradial  and  interdistichal  spaces  depressed.  Plates  convex, 
the  surface  covered  with  obscure  radiating  ridges,  and  the  central  jiortion  in 
most  of  them  produced  into  a  small  node. 

Infrabasals  small,  but  plainly  visible  beyond  the  column  ;  the  bottom 
somewhat  depressed  for  the  reception  of  the  column.  Basals  larger  than 
any  of  the  other  plates,  longer  than  wide  ;  the  lateral  upper  faces  longer 
than  the  lateral  lower  ;  the  upper  faces  rather  narrow.  Radials  larger  than 
the  costais ;  three  of  them  pentagonal,  the  two  posterior  ones  hexagonal ; 
the  costais  slightly  narrower  and  shorter.  The  distichals  support  the  free 
arms ;  five  to  six  of  them  take  part  in  the  calyx,  of  which  the  three  lower 
ones  are  subquadrangular  and  twice  as  wide  as  long,  the  two  or  tinee  suc- 
ceeding ones  cuneate,  and  .^ilightly  interlocking.  The  free  distichals  are  less 
convex  and  shorter  than  those  of  the  calyx ;  the  succeeding  arm  plates 
strictly  biserial,  and  very  short.  Arms  rather  stout  at  the  proximal  ends,  but 
the  size  decreases  rapidly  with  each  bifurcation.  There  are  two  bifurcations 
in  the  free  arms,  and  the  branches  are  widely  divergent.     The  large  plates 


' 


mi': 


236 


TIIK  (UINOIDKA  CAMKRATA  OF   NOIITII    AMKHICA. 


I  ^ 


iiitorpoMod  bi'twoi'ii  the  rft<liiiln  iiiv  IoIIowcmI  l»y  two,  tluoi',  and  tliroo  Intcr- 
hiacliiiilM  lit  tlio  ri'giiliir  .xidi-s  ;  wliilo  tliK  aniil  h'uIi'  has  throe  in  tlio  weeoinl 
niid  luiii'  ill  tiie  third  row.  Cuiisti-iictioii  of  ventral  disk  uiid  iinim  nut  i\nu\vn. 
Intura.\illarieH  tlnee  or  more. 

Jliirix'in  and  Loiuliti/. —  Hamilton  groiiii ;  C'anandaigua  lUid  Ontario  Cos  , 
N.  Y. 

I'l/jir  in  tlic  New  York  Slate  Cabinet  jf  Natural  IIi«tory  at  Albany. 

lidiiiii'kn.  —  Tiiis  form  dill'ers  from  the  otiier  Anieriean  species,  except 
lihinhirrliuiH  Kirhyi,  in  having  inleraxillary  i)lates,  and  also  in  the  details 
of  tho  arm  Htructurc.  Our  description  was  made  from  Hall's  figure,  ami 
from  ft  specimen  in  tho  collection  of  Prof.  J.  M.  Clark,  which  ia  now  in  tho 
New  York  State  Cabinet. 

Rhodoorinus  Kirbsri  W.  and  Si-. 
rhttc  XII.  Fi,js.  I(t,  h,  c,  d. 

188',».    Ocol.  Rep.  llliiiiiis,  V(,l,  VIII,  p.  ISO,  IMiilc  1.5,  Fig.  10  ami  riiite  10,  Fi«  3. 

Calyx  barrel-shaped,  a  little  longer  than  wide,  excavated  at  the  bottom, 
slightly  swelling  from  the  middle  of  the  ba.sals  to  the  middle  of  the  second 
costals,  thence  contracting  to  the  margin  of  the  tegmen.  In  some  specimens 
the  sides  are  almost  cylindrical.  Surface  of  plates  convex,  covered  with 
obscure  ridges  passing  from  plate  to  pinto ;  those  following  the  radial  series 
somewhat  stronger,  and  increasing  in  prominence  as  they  approach  the  nrin 
bases,  so  as  to  give  to  the  calyx  an  obscurely  pentangidar  outline. 

Infrabasals  concealed  by  the  column,  small,  resting  within  a  .shallow  con- 
cavity. Basals  large ;  their  lower  margins  abruptly  bent  inward ;  the 
middle  portion  forming  a  sort  of  rim  on  which  the  calyx  rests.  Kadials 
smaller  than  the  basals,  about  as  wide  ns  long.  Costals  two,  of  nearly 
iniiform  size,  about  half  the  size  of  the  radials.  Disticlmls  five;  the  t\. o 
lower  ones  incorporated  into  the  calyx,  smaller  than  the  costals;  the  three 
upper  ones  free,  very  short  and  rounded  exteriorly;  the  third  axillary, 
giving  off  two  branches,  of  which  only  the  inner  one  branches  again,  gener- 
ally from  the  third  plate,  giving  three  arms  to  each  main  division  of  the  ray, 
or  thirty  in  all,  with  occasionally  an  additional  arm  in  one  or  both  posterior 
rays.  Arms  cylindrical,  and  only  tapering  nt  the  tip,i;  they  are  composed 
of  a  double  series  of  rather  short,  interlocking  pieces,  with  indented  suture 
lines  which  give  to  the  back  of  the  arms  a  file-like  appearance.     Pinnules 


HIIODOCHIXID.K. 


227 


Mtrong,  contiguoiiM  ;  compoHi'd  of  t'l<)tij,'iite  juiiitn.  Intcrnulial  spaces  nnaiij^id 
in  four  rows.  Tlic  plates  iiilorpo^ed  l)utweeii  tlie  rutlials  Hinalli'i'  tliaii  tlu-MO  ; 
followud  by  two,  nuely  three,  iiiterbnicliiulH,  iiiul  tlier-o  hy  two  and  lliit'e 
otlierM  in  tlio  two  Miiceeeding  rowM,  wliieli  gradiiiilly  decrenHe  in  sizt'  iijiwardH. 
Aniil  Mido  wider,  witli  tiired  plates  in  the  Hecond,  imd  f^encrally  lour  in  the 
thinl  row.  Interdistichais  from  two  to  three,  very  Minall.  l)i>k  fijij^htly 
convex,  the  iulerriidial  spaces  a  little  depressed  ;  constructed  throu>;hout 
of  very  small,  irregularly  arrangeil  tumid  plates.  Anus  nimost  centrid.  at 
the  eml  of  II  wart-like,  somewhat  conical  prolrberance,  composed  of  very 
smidl  pieces,  Colunni  roiuid,  from  eight  to  ten  inches  long,  nearly  uniform 
for  ahout  two  thinls  its  length,  whence  it  gnuliially  tapers  to  ii  line  point, 
witli  a  few  sliort  cirri  given  oil'  toward  the  end.  The  joints  are  rounded 
along  their  edges,  and  the  nodal  ones  nro  a  little  the  wi<lest  and  longest. 

Horizon  and  Locdii/ij.  —  Kinderhook   group,  Lo  Grand,  Marshall   Co  , 
Iowa. 

7}/j)rs  in  the  collection  of  Wnchsmuth  and  Springer. 

Jiinnirkfi.  —  This  species  is  one  of  the  most  al)undant  at  the  Le  Grand 
locality,  where  many  specimens  have  been  ol)tained  with  crown  and  stem 
fully  preserved.  The  specimens  arc  invariably  of  a  very  dark  color,  though 
lying  in  contact  with  I'lnfi/crlniis  and  other  forms  which  are  light  colored, — 
sometimes  almost  as  light  as  tiiose  from  the  Burlington  r<)i'l<s.  'i'his  varia- 
tion in  color  of  the  fossils  is  one  of  tlie  interesting  facts  of  that  locality.  The 
Crinoids  must  have  been  deposited  there  in  very  quiet  waters ;  they  occur 
in  a  soft,  light  bulT  limestone,  and  in  many  cases  are  imbedded  just  as  they 
died.  They  occur  in  nests  or  colonies,  and  the  genera  and  sj)ecies  are  indis- 
criminately commingled,  there  being  of  Crinoids  and  Blastoids  upwards  of 
twenty-four  species.  It  is  therefore  a  singular  fact,  that  while  the  specimens 
of  some  species  are  of  a  pure  calcareous  composition,  and  of  very  light  color, 
those  of  others,  under  precisely  the  same  conditions  of  fossilization,  lying 
side  by  side  with  them  and  often  with  stems  and  arms  intertwined,  are 
harder,  and  of  a  very  dark,  brownish  or  even  purplLsli  grey  color.  The 
contrast  between  some  of  tliem  is  very  marked,  and  so  nearly  constant  for 
the  species  as  to  be  quite  a  reliable  feature  for  separating  them.  There  are 
intermediate  shades  of  color  between  the  lightest  and  the  darkest,  but  as 
a  general  thing  specimens  of  the  .same  species  have  a  uniform  shade.  As 
a  rule,  all  the  species  of  Arthiocrums,  Platycrinus,  Graph tocrlmis,  Scaphlocr'iHus, 
Taxocrimis  and  the  Blastoids,  are  of  light  color ;  Dori/crims  and  Dichocriiwfi 


r 


M 


228 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


.  i 

]  i 


are  dark,  and  Majlstocrhms  and  Bu'ocrimts  rather  intermediate ;  but  while 
llhuducrinua  Kirbiji  is  very  dark,  R.  nanus  is  liyht  colored,  and  li.  water- 
sianus  intermediate  between  them. 

Rhodocrinus  nanus  M.  and  AV. 

Plitic  XL,  Fi<js.  7a,  h ;  and  Plate  XII.,  Firjs.  2a,  h. 

1800.     Mkkk  iiiul  WoRTiiEN;  Proceed.  Acad.  Nut.  Sci.  Pliilu.,  \i.  251-. 

1808.     Mkkk  and  Wobtiikx;  GcoI.  Surv.  Illinois,  Vol.  111.,  p.  470,  Plate  IS,  Figs.  2a,  b. 

1885.     W.  and  Sp. ;  llcvisiou  Palicocr.,  Part  11.,  p.  212. 

1859.    AV.  and  Si'. ;  Geol.  Siiiv.  Illinois,  Vol.  VIH.,  p.  182,  Plate  Ifi,  Fig.  4;  and  Plate  17,  Fig.  15. 

S>u.  Rhuihi-riiiHs  seiilptiis  S.  A.  JIiLLEii;  1890,  Uescr.  New  Genera  and  Species  of  Ecliin.,  p.  42, 
Plate  7,  Fig.  11. 

Svn.  lUwilwriiiiis  ctrluliis  S.  A.  Mii.i.ER;  1890,  ibid.,  p.  43,  Plate  7,  Fig.  10. 

Calyx  siibglobose,  the  side.s  regularly  convex,  except  in  specimens  with 
very  protuberant  basals,  in  whicli  they  appear  to  be  nearly  straight ;  the 
base  triuicate  and  slightly  impressed.  The  plates  along  the  rays  marked  by 
rounded  ridges,  which  vary  somewhat  in  prominence.  These  ridges  in  some 
specimens  are  confined  almost  entirely  to  the  radial  series,  giving  to  the 
calyx  a  pentagonal  outline,  but  in  others  they  run  to  the  basals,  interradials 
and  anal  plates,  traversing  the  sutures,  and  pa.ssing  from  plate  to  plate.  The 
plates  are  more  or  less  convex,  and  their  outlines  well  defined. 

Infrabasals  small,  im[)ressed,  slightly  projecting  beyond  the  column. 
Basals  large,  a  little  protuberant,  the  calyx  resting  on  their  lower  margins, 
which  are  rounded  and  form  a  low  rim  around  the  concavity.  Radials  nearly 
as  large  as  the  basals ;  the  costals  about  of  equal  size,  but  one  third  smaller 
than  the  radials.  Distichals  generally  five,  of  which  only  the  first  and 
larger  one  takes  part  in  the  calyx ;  the  others  which  are  of  nearly  uniform 
size  and  quadrangular,  except  the  upper  which  is  axillary,  are  free  arm 
plates.  The  inner  branches  of  the  arms  divide  again  on  the  third  joint,  and 
there  is  also  occasionally  a  bifurcation  from  the  outer  branch  in  a  posterior 
ray.  The  arms  taper  but  little,  are  long,  and  biserial  after  the  last  bifur- 
cation. The  arm  joints  are  narrower  than  in  R.  Klrhyi,  and  their  backs  more 
rounded  ;  the  pinnules  stronger  and  less  closely  packed  than  in  that  species. 
First  interradials  half  the  size  of  the  radials ;  followed  by  two  interbrachials 
nearly  as  large ;  the  succeeding  plates  considerably  smaller,  and  their  ar- 
rangement somewhat  irregular.  Anal  interradius  wider  than  fhe  others,  and 
enclosing  a  continuous  row  of  anal  plates,  which  rest  upon  the  truncated 
upper  face  of  the  interradial.  The  first  anal  plate  is  as  large  as  the  radials, 
but  the  interbrachials  at  both  sides  of  it  are  smaller  than  the  corresponding 


RHODOCRINIDiE. 


229 


plates  of  the  other  areas.  Anal  opening  exccntric,  directed  upwards,  placed 
within  a  large  protuberance,  composed  of  rather  large  plates.  Ventral  disk 
convex,  depressed  at  the  interradial  spaces,  and  constructed  of  small,  irre- 
gular, convex  pieces  without  definite  arrangement. 

Horizon  and  ioca%.  —  Kinderhook  group;  Le  Grand,  Marshal  Co.,  and 
Burlington,  Iowa. 

Types  in  the  Museum  of  Comparative  Zoology  at  Cambridge,  and  in  the 
collection  of  Wachsnjuth  and  Springer. 

Jiemarks.  —  This  species  is  nearest  allied  to  E.  Kirliji,  from  which  it  is 
distinguished  by  its  more  globose  form,  more  slender  arms,  by  the  ridge- 
like series  of  anal  plates,  and  the  absence  of  interaxillaries.  In  the  Le  Grand 
beds  this  species  is  readily  identified  by  its  color,  which  is  invariably  light; 
while  all  specimens  of  i?.  Kirhi/i  are  dark  colored,  and  those  of  E.  tvalcrsiamis 
intermediate  between  the  two. 

Bhodocrinus  parvus  s.  A.  Millkr. 

1891.    S.  A.  MiLLEiii  Gool.  Kcp.  Missouri,  Bull.  4,  p.  39,  Plate  5,  Figs.  8,  9. 

Closely  allied  to  i?.  nanus,  but  a  somewhat  smaller  species  and  the  calyx 
more  depressed.  Calyx  subglobose,  wider  than  high  ;  the  plates  moderately 
convex,  and  covered  in  exceptionally  well  marked  specimens  by  ob.scure 
ridges*  passing  from  plate  to  plate;  suture  lines  distinct.  Infraba.sals  slightly 
extending  beyond  the  column.  Basals  the  largest  plates  of  the  calyx,  bend- 
ing gradually  upward.  Radials  nearly  as  large  as  the  basals.  The  two 
costals  together  smaller  than  the  radials,  and  frequently  anchylosed.  Dis- 
tichals  five,  very  small,  only  the  first  a  calyx  plate,  the  succeeding  ones  free ; 
the  upper  axillary,  and  supporting  two  arms,  which  do  not  branch  again. 
Arm  openings  arranged  in  pairs,  each  pair  separated  by  a  wide  interspace. 
Arms  delicate,  composed  of  two  series  of  deeply  interlocking,  cuneate  pieces, 
the  intervening  sutures  grooved.  Pinnules  not  in  contact  laterally.  The 
plates  interposed  between  the  radials  very  large,  especially  that  of  the  anal 
side  Interbrachials  2,  3,  and  2,  apparently  also  at  the  anal  side.  The 
ventral  disk  not  exposed  in  the  specimens. 

Horizon  and  Locality.  —  Lower  part  of  Warsaw  limestone;  Booneville,  Mo. 

TyiKs  in  the  collection  of  Mr.  S.  A.  Miller. 

•  We  nre  leil  to  Relieve  tlint  tlic  ridfjes  in  Jliller's  (iffurcs  are  too  distinct  and  inislcadinf;.  In  fivi'  speci- 
mens in  the  Missouri  State  collection  with  Jliller's  label  attached,  there  are  no  ridc;es  at  all,  and  I  he  surl'iiee 
is  smooth  or  slightly  roughened.  That  this  is  not  owing  to  the  preservation  is  sliowu  by  the  I'lict  thai  llie 
other  parts  are  sharply  defined. 


r 


i( 


230 


THE  CllINOlDEA  CAMERATA  OF  NORTH  AMERICA. 


RhodoorinuB  Barrisi  Hall. 
Plate  XII.  Fiffs.  3, 4a,  b,  c,  d ;  and  5a,  h. 

1861.    Hali;  Prelim.  Notice  of  New  Spec,  of  Criii.  (Allmiiv),  p.  9. 
ISOl.     lUu,;  Boston  imm.  Nat.  Hist.,  Vol.  YII.  (No.  2),'  p.  'Hi. 
1872.     Hall;  N.  Y.  SIntc  Miis.  Nut.  Hist.,  Bull.  1,  Plate  C,  Figs.  16,  17. 
1S81.     W.  ami  Sp.;  Kevisioii  Pulieoer.,  Part  II.,  p.  212. 

Sjii.  Rlwilocrhiiiii  Barrisi,  var.  ditergeiis  Hall,  1801;  Boston  Jouru.  Nat.  Ilist.,  Vol.  VII.,  p. 
321;  ami  N.  Y.  State  Mus.,  Bull.  1,  Plate  6,  Tig.  18. 

A  very  variable  species,  of  the  style  of  Gilbertsocrimts.  Calyx  forming 
a  polyhedron,  with  slightly  impressed  faces  and  a  node  at  each  angle.  Dorsal 
cup  broadly  truncate  at  the  bottom,  widest  at  the  middle  of  the  radials, 
whence  it  tapers  rapidly  and  uniformly  to  the  margins  of  the  tegmen,  whose 
diameter  is  from  one  third  to  one  half  smaller  than  that  of  the  widest  part 
of  the  dorsal  cup,  and  less  than  the  diameter  at  the  truncated  lower  part. 
Plates  highly  elevated,  their  middle  portions  crowned  with  spine-like  pro- 
cesses or  elongate  nodes,  connected  by  well  marked  ridges,  which  traverse 
the  sutures  and  meet  with  the  nodes  of  adjoining  plates.  The  nodes  upon 
the  basals  are  longer,  attaining  in  very  mature  specimens  a  length  of  four  to 
five  mm.  by  two  mm.  wide ;  they  are  directed  oblifjuely  downward,  while  those 
from  the  radials,  costals,  and  interradials  point  horizontally.  In  less  mature 
specimens,  as  a  rule,  the  nodes  are  comparatively  smaller.  The  ridges 
connecting  the  basals  form  around  the  bottom  of  the  calyx  a  well  defined 
pentagon,  with  a  shallow  concavity  occupying  the  whole  width  of  the  lower 
face,  enclosing  the  infrabasals  and  fully  one  third  of  the  basiils. 

Infrabasals  small,  but  their  upper  angles  visible  beyond  the  column. 
Basals  proportionally  large ;  their  upper  half  abruptly  bent  upwards  so  ns 
to  take  part  in  the  lateral  walls,  and  forming  a  sharp  edge  on  which  the 
caly.x  rests.  Radials  a  little  smaller  than  the  basals.  Costals  very  small  ; 
the  first  less  than  one  third  the  size  of  the  radials,  but  twice  as  large  as  the 
second.  Distichals  eight  to  twelve ;  the  plates  of  the  first  row,  and  some- 
times those  of  the  second,  incorporated  into  the  calyx  and  in  contact  later- 
ally. The  free  distich.als  short,  cuneate,  and  in  large  specimens  interlocking ; 
the  upper  one  axillary,  supporting  two  arms,  of  which  either  one  or  both  are 
branching  once  again.  Arm  openings  elongate  ;  arranged  in  pairs  ;  directed 
horizontally.  Arms  about  twice  as  long  as  the  height  of  the  calyx ;  cylin- 
drical ;  somewhat  divergent ;   the  plates  sharply  cuneate  and  interlocking. 


I  'i 


RIIODOCRIMDiE. 


231 


Pinnules  contiguous ;  their  joints  as  long  as  two  of  the  arm  plates.  First 
interradial  followed  by  two  rows  of  iuterbrachials  of  two  each,  except  at  the 
anal  side,  which  has  from  three  to  four  plates  in  the  second  row ;  the  first 
almost  as  large  as  the  radials  ;  the  succeeding  ones  very  much  smaller.  Yen. 
tral  disk  slightly  elevated,  flnttened  in  the  middle ;  composed  of  fourteen  to 
sixteen  rather  large  convex  or  conical  plates,  indefinitely  arranged.  Anus 
marginal,  directed  obliquely  upwards.  Column  short,  gradually  tapering ; 
joints  moderately  high,  the  edges  almost  straight. 

Horizon  and  LomVdij.  —  Upper  Burlington  limestone  ;  Burlington,  Iowa. 

Types  in  the  Museum  of  Comparative  Zoology,  Cambridge. 

Bemarlis.  —  The  specimen  described  by  Hall  as  variety  dkcrrjms  is  a  very 
mature  form  of  this  species.  In  the  smaller  specimens  the  branches  of  the 
arms  are  less  divergent. 

Rhodoorinus  Barrisi  var.  striatus  W.  &  Sp. 

Plate  XIL  Fifj.  6. 

Calyx  almost  cylindrical,  broadly  truncated  at  the  bottom,  but  not  exca- 
vated. Plates  moderately  convex,  without  nodes.  Surface  covered  witli 
well  defined  ridges,  which  meet  with  similar  ridges  from  adjacent  plates. 
The  ridges  connecting  the  basals  and  those  proceeding  from  the  radials  to 
the  adjoining  basals  forming  a  triangle,  which  encloses  another  whose  ridges 
are  somewhat  less  distinct.  The  form  and  arrangement  of  the  plates  simi- 
lar to  those  of  the  typical  form,  but  the  ventral  disk  proportionally  larger, 
and  composed  of  a  greater  number  of  pieces. 

Horizon  and  LocaUti/.  —  Upper  Burlington  limestone  ;  Burlington,  Iowa. 

Type  in  the  collection  of  Wachsmuth  and  Springer. 

Rhodoorinus  truncatus  w.  &  Sp.  (nov.  spec). 

Piute  XIII .  Fiffs.  2a,  b,  c,  d,  c,  /. 

A  rather  small  species.  Calyx  wider  than  high,  pentangular  in  outline, 
broadly  truncated  at  both  one's ;  the  sides  nearly  parallel,  a  little  wider  at 
the  arm  bases.  The  truncation  of  the  lower  end  not  only  extends  to  the 
greater  part  of  the  basals,  but  includes  small  portions  of  the  radials.  The 
base  is  pentangular  in  outline,  not  excavated,  except  the  middle  part  very 
slightly  for  the  reception  of  the  column.     Plates  convex,  a  little  tumid,  with 


r 


fi'^ 


u 


232 


THE  CRINOIDKA  CAMERATA  OF  NORTH  AMERICA. 


obscure  ridges  or  angularities  passing  out  from  their  margins,  and  meeting 
tliose  of  adjoining  plates  ;  the  median  portions  perfectly  smooth. 

Basals  and  radials  of  nearly  the  same  size,  both  bending  abruptly  upward, 
the  former  to  three  fourths  their  length,  the  others  only  at  the  lower  ends. 
Costals  one  or  two ;  togetlier  about  one  half  the  size  of  the  radials,  very 
frequently  anehylosed,  there  being  scarcely  a  specimen  with  two  costals  in 
all  five  rays.  Of  the  distichals  generally  but  one  plate  takes  part  in  the 
calyx  —  in  very  large  specimens  sometimes  two  —  which  is  as  large  as  the 
second  costals.  Arm  openings  two  to  tha  ray,  facing  sideways.  Arms  un- 
known. Interradial  spaces  fiattened,  composed  of  1,  2,  3  plates,  followed  by 
two  others  between  the  arm  openings ;  the  plate  between  the  radials  not 
larger  than  the  interbrachials  above ;  the  two  latter  separated  by  a  shallow 
depression,  which  gives  to  the  arm  bases  a  somewhat  lobed  appearance,  and 
to  the  tegmen  a  pentangular  outline.  Anal  side  wider,  with  three  plates  in 
the  second  row  ;  the  plates  of  the  median  row  forming  a  vertical  ridge  of  five 
pieces,  which  passes  up  into  the  tegmen.  Ventral  disk  comparatively  large, 
almost  flat;  composed  of  about  twenty  slightly  convex  plates,  of  which 
those  near  the  margin  are  the  largest.  Anus  marginal,  on  top  of  a  small 
protuberance. 

Ilorizon  and  Localltif.  —  Upper  Burlington  limestone  ;  Burlington,  Iowa. 

Types  in  the  collection  of  W.achsmuth  and  Springer. 

Remarks.  —  This  species  resembles  the  two  preceding,  but  differs  essen- 
tially in  the  form  and  proportions  of  the  calyx.  In  those  species  the  calj'x 
attains  its  greatest  width  in  the  lower  half  of  the  dorsal  cup,  and  the  teg- 
men is  proportionally  narrow ;  while  in  this  species  the  calyx  is  widest  at  the 
bases  of  the  arms.  Besides  it  differs  in  the  construction  of  the  anal  side,  and 
in  having  larger  costals  and  distichals. 

Bhodocrinus  tuberculatus  w.  &  Sr.  (uov.  spec). 

Plate  XIII.  Figs.  3,  4. 

A  very  knobby  species ;  somcvhat  larger  than  the  preceding  one. 
Calyx  a  little  liigher  than  wide ;  deeply  excavated  at  the  bottom  ;  decid- 
edly bulging  at  the  costals,  whence  it  contracts  uniformly  to  the  margin  of 
the  ventral  disk,  where  the  diameter  is  fully  one  third  smaller  —  less  than  the 
width  at  the  lower  end  of  the  dorsal  cup.  All  plates  of  the  calyx,  basals 
and  infrabasals  excepted,  extended  into  conspicuous  angular  tubercles,  of 
which  those  upon  the  radials  are  longest  and  stoutest. 


RIIODOCRINIDTI-:. 


28a 


Infrabasals  placed  >t  the  bottom  of  a  concavity ;  forming  n  penta- 
gon, of  wliich  small  portions  are  exposed  beyond  the  colunni.  Basals 
smaller  than  the  radials  and  without  nodes  or  tubercles ;  they  rest  within 
the  lower  concavity,  except  their  extreme  upper  ends,  wliich  bend  slightly 
upwards.  Radials  large,  forming  a  rim  upon  which  the  calyx  rests;  their 
tubercles  quite  long,  rounded  at  the  ends,  and  directed  obliquely  downward. 
Costals  comparatively  large,  their  tubercles  connected  with  one  another,  and 
sometimes  with  those  of  adjoining  radials  and  interradials  by  obscure  ridges. 
Distichals  one  in  the  calyx,  provided  with  a  horse-shoe-shaped  facet  lor  the 
reception  of  the  free  brachials.  Arm  openings  elongate,  facing  laterally ; 
structure  of  the  arms  unknown.  First  interradial  followed  by  interbrachials 
in  succession  of  2,  2,  and  two  more  between  the  arm  openings.  The  anal 
interradius  has  three  plates  in  the  second  and  succeeding  rows,  but  the  plates 
are  not  formed  into  a  ridge  or  placed  in  a  straight  line,  their  arrangement 
being  rather  irregular.  Interdistichals  one,  on  a  level  with  the  arm  openings. 
Togmen  very  small,  flat,  and  of  the  plates  only  the  ends  of  the  tubercles  vis- 
ible from  a  side  view ;  the  plates  large  and  irregularly  arranged.  Anal  open- 
ing marginal. 

Jlorhon  and  Locnlity.  —  Age  of  the  Lower  Burlington  limestone,  Lake 
Valley,  New  Mexico. 

Ti/2)es  in  the  collection  of  Wachsmuth  and  S])ringer. 

Bcmarl-ii.  —  This  species,  which  has  the  general  habitus  of  certain  forms 
of  Gi/krtxocriiws,  differs  from  all  other  speci''s  of  Bhodorrnnis  in  the  form  of 
its  nodes,  which  cover  almost  the  whole  face  of  the  jdates.  The  largest 
nodes  occur  on  the  radials,  and  not  on  the  basals,  those  of  the  latter  plates 
being  often  wanting  altogether.  It  also  differs  in  the  form  and  greater  size 
of  the  costals  and  distichals. 


;  r 


GILBERTSOCRINUS  Phillips. 


1830.     Pilll.Lirs;  Gpolofry  of  Yorksliire,  Part  II.,  p.  20?. 

1811.     MuLLKii;  Berlin.  Acnd.  ilcr.  Wissenscli.,  p.  209. 

18W.     U'OiiiiiONv;  Piralrumc  I.,  p.  155. 

1852.     U'Oiiiur.NV  ;  Cours  olemeiit..  Vol.  II.,  p.  142. 

1905.     Meek  nnd  AVoktukn  ;  Proceed.  Acad.  Nat.  Sci.  Pldln.,  p.  166. 

1872.     H.U.I.;  N.  Y.  Slate  Mils,  of  Nat.  llisl..  Bull  I.,  Plate  hi  and  Plate  VI. 

1S73.     Meek  and  Woutiien;  Geol.  Uep.  Illinois,  V(d.  V.,  p.  3S9. 

1875.     Grenfei.i,  ;  Proceed,  of  Bristol  Naturalists'  Soc,  Vol.  I.,  Part  III.,  p.  483. 

Syn.  O/ZmT/BOT  CiMiiKUi,.\Nn  ;  1820,  Appendix  to  Reliqnin?  Conservain!,  Plate  D  ;  1877,  Waclisnmlli; 
Anier.  Jonru.  Sci.,  Vol.  XIV.,  p.  125  ;  1S7S,  Zittel ;  llandh.  d.  Palaeont.,  Vol.  I.,  p.  376  ;  1^81, 
W.  ami  Sp. ;  Uevislon  Palifoer.,  Part  II.,  p.  213;  and  Proceed.  Aead.  Nat.  Sei.  I'liila.,  p  387; 

.30 


i 


i 


1; 


234 


,  i-'i 


THE  CRINOIDEA  CAMERATA  OF  NOUTH  AMERICA. 

1885,  \V.  BiidSp. ;  llcvision  Pulicocr.,  I'lirt  111.,  p.  99 ;  niul  Proceed.  Acad.  Nut.  Sci.  Philii 

p.  321. 
Syii.  Rhodocriiius  Ue  Kon.  mid  Lk  Hon,  1853,  Kcclicr.  t'riii.  Curb.  Uelg.,  ji.  lUt;  llnciner,  185.). 

LetliiRU  Ocogiioht.,  p.  240  ;  I'ictot,  1857,  Tniite  dc  I'aleont.,  Vol.  IV.,  p.  311 ;  E.  Hillings,  185S, 

Canada  Surv.,  Decade  III.,  ])p.  25  k  •ifi;  Dujardiu  and  llnpe,  1802,  Hist,  natur.  des  Zooplivtn 

Erliiuod.,  p.  123;  Kofc,  1865,  (Jeol.  Magazine,  No.  12,  p.  217. 
Syn.  Oonittsleroitloeriiiua  LvoN  and  C.iS.sKinY,  1S59,  Amer.  .lourn,  Sci.,  Vol.  XXVIII.,  Scr.  2,  p.  233; 

Meek  and  Worllicn,  1809,  Proceed.  Acad.  Nat,  Sci.  I'liilu.,  p.  73  ;  S.  A.  Miller,  1877,  Calal. 

Palffioz.  Foss.,  p.  80,  mid  1889,  N.  Am.  (ieol.  and  I'aliconl.,  p.  219. 
Syn.  Tremntorriniis  Hai.1.,  1800,  Siippl.  Geol.  Itrp.  Iowa,  Vol.  1.,  p.  70,  and  Prelim.  Notice  of  New 

Spec.  ofCrin.,  p.  9;  Meek  and  Wort  lien,  1800,  Proceed.  Acad.  Nat.  Sci.  Pliila.,  p.  3SH ;  Hall, 

1861,  Jonrn.  Host.  Soo.  Nat.  Hist.,  Vol,  VII.,  p,  325,  and  1802,  24tli  Hep.  N,  Y.  Stale  Cab. 

Nat.  Hist,,  p.  128;  Meek  and  Wortheii,  1806,  Geol.  Kep.  Illinois,  Vol.  II.,  p.  217. 


.7/?A., 


Fig.  11.  —  Gilberhoerinu!. 

lb  =  infrabasals,  b  =  basals,  R  =  radials,  I  =  costals,  II  =  distielials,  TIT  =  palmars,  A  =  arms,  AO  =  ami 
openings,  ir  =  interrndials,  ibr  =  iiilcrbrachials,  IUA  =  iiitcrradial  appendages. 


Dorsal  cup  greatly  exceeding  the  disk  in  size ;  the  former  elongate,  more 
or  less  cylindrical ;  the  latter  flat  or  low-hemispherical,  its  margin  extended 
into  ten  tubular  appendages,  passing  outward  and  downward.  Plates  smooth 
or  radiated,  nodose  or  spiniferous. 


RHODOCRINIDVE. 


286 


Infrabasftls  five,  small,  pentagonal ;  forming  a  flat,  impressed  pentagon 
at  the  bottom  of  a  concavity.  Basals  large,  heptngonal,  widely  truncate 
above.  Radiuls  angular  at  the  bottom.  Costals  two.  Distichals  2  X  10  in 
the  calyx ;  the  upper  ones  excavated  to  form  the  lower  niargin.s  of  the  arm 
openings,  of  which  there  are  two  to  the  ray,  one  to  each  main  division.  The 
arms  are  in  clusters,  delicate,  branching  and  biserial  from  the  last  axillary ; 
they  either  stand  erect  cand  fold  over  the  disk,  or  are  pendent,  their  ventral 
furrows  exposed  to  view.  Pinnules  rather  strong  and  closely  packed  to- 
gether. Interradial  areas  large,  composed  of  numeious  plates;  those  alter- 
nating with  the  radials  considerably  larger  and  frequently  nodose,  the 
inter!,  ihials  arranged  in  vertical  rows.  Anal  intcrradius  generally  not 
distinct  in  the  cup. 

Ventral  disk  nearly  flat,  with  five  pit-like  int(  dial  depressions,  of  which 
the  posterior  one  is  considerably  the  largest ;  the  bottom  of  the  pits  formed 
by  small  polygonal  pieces,  surrounded  by  larger  plates.  In  the  European 
species,  in  which  the  pits  are  less  conspicuous  or  even  wanting,  the  disk 
plates  differ  but  little  in  size.  The  outer  margins  of  the  disk  are  extended 
outward,  and  form  ten  large  tubular  appendages,  which  are  pendent,  in  some 
species  reaching  down  below  the  calyx.  These  appendages  are  formed  either 
by  a  single  row  of  cylindrical  joints,  or  by  throe  rows  of  plates  longitudinally 
arranged,  two  of  them  ventrally  disposed,  the  third  dorsally  ;  but  when  two 
of  them  are  suturally  connected,  the  consolidated  part  is  composed  of  two 
and  six  plates  respectively,  iae  tubes  are  all  pierced  to  their  full  length 
by  a  central  canal,  which,  on  entering  the  calyx,  connects  with  the  sub- 
tegminal  grooves  at  the  inner  floor  of  the  disk.  In  the  European  species, 
the  ten  appendages  are  free  from  their  origin  in  the  calyx,  and  those  facinr^ 
the  same  intcrradius  are  separated  from  each  other  by  interradial  platr^.  In 
the  American  forms,  however,  with  the  exception  of  G.  s/iiiiiffcnt^  from  the 
Hamilton,  and  G.  Jiscvlhis  from  the  lower  Burlington,  the  tubes  meet  in  piiirs 
at  midway  between  two  rays,  and  are  for  some  distance  laterally  connected 
by  a  rigid  suture ;  but,  although  apparently  forming  a  single  a])pendage, 
each  one  from  the  base  up  has  its  own  canal,  and  the  two  canals  of  the  same 
set  connect  with  different  ambulacra.  The  arm  or  ambulacral  openings  are 
located  beneath  the  appendages;  they  occupy  the  bottom  of  a  small,  funnel- 
shiiped  pit,  and  are  formed  betw.een  the  .second  distichals  and  the  proximal 
])lates  of  the  appendages.  Anus  subcentral.  opening  out  directly  through 
the  togmen,  and  occupying  the  upper  (inner)  end  of  the  posterior  depression. 


r 


236 


TIIK  CHINOIDKA  CAMP:RATA  OF  NORTH  AMERICA. 


Ornls  of  latlu'r  ini'giilar  arraiigcinent,  and  their  iduiitification  NOtnetiineH 
ilifficult  in  certain  wpccio''. 

Column  circular;  the  nodal  joints  considerably  wider  and  higher,  rounded 
,  at  their  edges;  axial  canal  pentalobate  or  stellate,  the  angles  directed 
radially. 

Distribution.  — Gilbcrtmcrlnm  occurs  in  America  and  Europe.  It  first  ap- 
peared in  the  Hamilton  group,  reached  its  climax  in  tlic  two  Burlington 
beds,  and  became  extinct  before  the  close  of  the  Keokuk  epoch. 

licniurks . —  The  name  OUdcrimis,  the  earliest  name  given  to  this  form, 
was  proposed  by  Cumberland  in  18'20,  in  an  appendix  to  the  Reli<|ui£B  Con- 
servatiu.  lie  published  no  generic  diagnosis  or  specific  name,  but  gave  an 
excellent  figin-e,  by  which  the  type  is  easily  identified.  Of  the  plate  con- 
taining this  figure,  however,  we  have  been  informed  by  the  late  Dr.  P.  H. 
Carpenter  that  only  a  few  copies  were  distributed  in  a  private  way,  and  that 
no  copy  of  it  is  to  be  found  in  the  Library  of  mc  British  Museum.*  For  this 
reason  it  cannot  be  looked  upon  as  lawfully  published,  and  the  name  will 
have  to  be  given  up. 

Phillips  proposed  the  genus  Gilbert sociinm  in  1836.  He  included  in  it 
Ciunberland's  type,  which  he  described  as  G.  cakaratiis  (PI.  XV.  fig.  5).  His 
figures  are  fairly  good,  but  the  descriptions  are  meagre,  and  show  no  essen- 
tial departures  from  Ithodocrinus.  Neither  does  he  make  any  allusion  to  the 
two  diflerent  sets  of  openings,  which  are  so  well  represented  in  his  figures. 
The  arms  are  described  as  "  rounded  and  perforated  in  the  centre." 

De  Koninck  and  Le  Hon,  in  1854,  declared  that  OUacriiius  and  Gilbert- 
Kocriiim  were  synonyms  of  lifiodocriniin.  They  probably  arrived  at  this  con- 
clusion from  their  "  Rhodoerimis  n/elldm"  which  we  find  to  be  a  true  Gilbert- 
socrinus  (PI.  XV.,  fig.  4).  Similar  views  were  expressed  by  Roemer,  Pictet, 
and  Dujardin  and  Ilupe. 

In  1859,  Lyon  and  Casseday  described  a  new  species  from  the  Carbon- 
iferous of  Kentucky,  and  made  it  the  type  of  a  new  genus :  Goniasteroido- 
crimis.  The  species  closely  resembles  that  figured  by  Cumberland  and 
Phillips,  except  that  the  supposed  arms  (appendages)  are  suturally  connected 
by  their  sides,  in  pairs,  for  some  distance  ;  while  those  of  the  Briti.sh  species 
are  separate  from  their  origin.  Lyon  and  Casseday's  specimen  was  in  excel- 
lent preservation,  the  so-called  arms  being  .all  in  position,  and  it  had  below 
and  between  these  "  arms,  in  the  interradial  fields,"  as  they  state,  clusters  of 

•  We  saw  it  iu  the  Cambridge  copy  wliicb  was  formerly  in  Do  Koiiinck's  library. 


i 


■..ii 


m 


RIIODOCUlMn.K 


237 


from  five  to  seven  "long  pemluluuH  cilia"  bearing  Jolicate  pinnules.  The 
pinnuliited  "  cilia"  tliey  aftoivvards  refer  with  ii  query  to  urinM. 

Hall  in  1860,  without  nmking  any  conipaiison  willi  Giiuiustei-ouhcrinm, 
described  under  the  new  name  IVemutwrinus,  a  number  of  specieH  from  the 
Subcarboniferous,  of  undonbteil  generic  identity  with  Lyon's  specieH.  lie 
also  regarded  the  upper  api)endiiges  as  arms,  but  doubted  if  tin.'y  could  have 
performed  the  functions  of  arms.  lie  further  suggested  that  probably  the 
•' foramina"  above  t'.ie  secondary  radials  served  for  the  protrusion  of  '•  lleshy 
arms  or  tentacles."  However,  a  year  or  two  later  he  described  his  Tixmuiu- 
crinus  Hpiniyeriix  with  '•  summit  arms"  and  '•  true  arms." 

In  I8G0,  Rofe,  who  apparently  was  not  acquainted  with  the  writings 
of  Lyon  and  Hall,  while  discussing  certain  morphological  questions,  assorted 
that  Phillip-!'  species  of  GilhcytaocrmiiH  "  are  undoubtedly  lllmhcr'nn."  He 
also  stated  that  lihoducruwa  differs  from  most  of  the  other  Crinoids  "  in  the 
form  of  the  arms  and  in  the  position  of  the  ovarian  apertures."  and  that 
"the  arms  have  no  grooves  on  the  upper  side,  but  are  cylindrical,  with  a 
tubular  canal  through  thj  a.\is,  and  the  ovarian  openings  placed  immediately 
under  the  ba.so  of  the  arms."  In  reply  to  Billings'  supposition  that  the 
upper  appendages  might  possibly  be  spines,  he  said  :  "  their  articulated  struc- 
ture, and  the  passage  through  the  a.\is  forbid  the  idea  of  their  being 
spines." 

Meek  and  Worthen,  in  I860,*  discriminated  between  Gil/icrtsocriiuis  and 
Gomaatcroidocrinus ;  making  the  latter  a  section  of  the  former.  Gilkrisorri- 
mis  was  said  by  them  to  have  the  "  p,seudo-ambulacral  appendages  "  located 
directly  over  the  interdistichal  spaces,  and  Goiiiat^toyndocriniis  over  the  inter- 
radial  ones;  and  they  sta  "d  that  these  structures  are  not  rrms,  that  they 
"  differ  essentially  from  all  appendages  of  the  body  in  any  known  Crinoid, 
and  .seem  to  bear  somewhat  the  same  relations  lO  the  body,  that  the  side 
branches  of  the  column  o(  Pciitacriniis  and  many  Palaeozoic  Crinoids  do  to  the 
column  itself."  The  "  true  arms,"  they  say,  connect  with  the  calyx  at 
the  lower  openings,  which  Hall  described  as  foramina  in  IWiiiatocriiius. 
They  gave  a  description  and  good  figures  both  of  the  true  arms  and  the 
appendages. 

Grenfcll,  in  1875,  defined  GiUiertsocriinis  as  follows :  "  Bnsals  five ;  sub- 
radials  five  ;  radials  three  ;  brachials  several,  generally  irregular  ;  the 
second  brachial  channelled  at  top,  and  leading  into  an  orifice  which  com- 

Geol.  Rep.  Illinois,  Vol.  II.,  pp.  219-221. 


u* 


M 


n 


' 


288 


TIIK  CUINOIDEA  CAMEUATA  OF  NOUTH   AMERICA. 


mimicntes  witli  t!io  porforiition  in  the  uriiiH;  axillary  plates  well  developed  ; 
arms  round  and  'oiierally  set  iit  right  angles  to  the  body."  Ho  took  the 
upper  openings,  /  c,  the  central  perforation  following  the  median  line  of  the 
appendages,  to  be  "elTerent  tubes, "  carryiin'  off  the  water  ii>ed  for  respira- 
tion, which  he  thinks  in  oth':r  grcps  is  performed  by  the  anal  tube. 

From  numerous  specime  ^  '»  ur  collection,  some  of  them  with  all  of  the 
two  kinds  of  rppendages  ^  ed  to  their  full  length,  we  are  enabled 
to  fully  confirm  ilie  opini  "i"  '  .-ek  and  Worthen  that  the  smaller,  pinnule- 
bearing  appendages  are  r  n-  id  that  the  stouter,  tubular  ones  are  struct- 
ures unlike  those  of  other  Ci'ii'  ids.  What  ♦he  functions  of  these  tubes  may 
have  been  can  only  be  co.  j  tured,  but  they  were  jjroltably  not  identical 
with  tiiose  of  the  cirri,  as  Meek  and  Worthen  supposed  ;  and  we  are  inclined 
to  think,  from  the  fact  that  their  canals  conmninicate  with  the  subtegminal 
galleries  at  the  inner  floor  of  the  ventral  disk,  that  the  functions,  as  sug- 
gested by  Grenfell,  were  respiratory,  anil  that  the  canals  performed  a  similar 
ollice  to  that  of  the  respiratory  pores  of  Jiafucrimia  and  the  spiracles  of  the 
Blastoids. 

Meek  and  Worthen,  in  separating  the  Europoon  species  from  the  Ameri- 
can, were  i)robal)ly  not  aware  that  the  coalesced  appendages  are  actually 
pairs  of  distinct  tubes,  each  one  having  a  canal  of  its  own,  and  the  canals 
of  the  same  pair  communicating  with  diiTerent  ambulacra,  in  a  way  similar 
to  that  of  the  paired  spiracles  in  the  Blastoid  genus  Pcutraidtcs.  It  is  in  this 
respect  exceedingly  interesting  that  in  (rilbcr/socn'nm  /lirtl/iis  the  posterior 
appendages  are  simple,  and  are  widely  separated  by  a  row  of  anal  plates, 
exactly  as  in  the  Emopoan  species ;  while  those  of  the  four  other  sides  are 
iniited  at  the  base.  The  species  thus  represents  at  two  of  its  sides  the 
Einopean  form  of  the  genus,  and  at  the  other  three  the  American. 

Another  interesting  fact  in  the  developmental  history  of  the  genus  is 
that  in  the  species  of  the  Burlington  limestone  the  consolidated  tubes  are 
composed  of  the  single  cylindrical  plates  of  two  simi)le  tubes  united  laterally 
by  suture.  In  the  transition  beds  between  the  Burlington  and  Keokuk 
groups  appears  the  rare  species  G.  oborti/iis,  in  which  the  two  rows  of  plates 
composing  the  double  tubes  of  its  predecessors  are  roofed  over  by  four  more  ; 
and  this  character  becomes  constant  in  the  Keokuk,  where  the  genus  is 
found  quite  abundant  in  .some  localities. 

The  genus  lihoJocrbiiia.  which  has  been  so  frequently  confounded  with 
Gilbertsocriinia,  has  arm  openings  only,  the  tubular  appendages  being  un- 
represented ;  otherwise  the  two  genera  cannot  be  distingui.shed. 


■ 


wl 


KIIODOCIMNID.K. 


23!J 


• 


Oilbertsoorlnua  tuberosua  (Lvov  mid  Casm.). 
Plate  XV.  Fl<js.  Ja,  >> ;  I'littc  XVI.  Flyx  1  to  C ;  J'lule  XVII.  Fhj.  G. 


1800.     Ouniunli'iniduirinU'  liilirra-iii^  —  LvoN  iiiiil  Cammk.dw;   Aincr.  Joiini.  Sci., 

2:t:i. 
1866,     OlHierlmcriiiHn  (OuHiiisleroiducr.)  luUrumix  —  Mkkk  niul  Worth KN  ;  (linl 

2:20,  will)  (|{ii(tmiii.s, 
1831.     Otliirriiiim  liiln-rmim—W .  niid  Sr.  ■,  Ucvisioii  riilii'iin-,,  I'l.  \\.,  ,  219. 
18S0,      Ooiiiinlrroidiii-riiiim  lu/n'ruiim —  H.  A.  Mir.l.Klij  N.  A.  (i((il.  and   I'lilii'oiil., 
Slice(«  I7tli  Ut:  flcdl,  Siirv.  Iiidiiuj;!,  .  ,-il,  I'liitc  ',),  V'li:.  11. 
Sjin.     TremiilocriiiHi  rultmtus  IIai.i,;  IsOO,  Sul.  (Icol.  I(c.  Imva,  .  77. 


Vol.  X\  VI II.,  (Scr,  2), 
He,  liliiiuis,  V(il   II..  . 

.  «0;  mid  l^ni,  Adv. 


Calyx  large,  a  little  liiglier  tlian  wide.  Dor.siil  cup  siibcylindncal, 
slightly  constricted  at  the  nrin  regions,  it.s  lm-<e  dooplv  excavated.  Ventral 
di,sk  flat,  with  deep  interradial  depressions;  the  appendages  pendent,  long, 
and  frequently  branching.  Plates  tumid,  the  radials  drawn  out  into  elon- 
gate  nodes  or  obtu,so  npines,  directed  downward. 

Infrabasals  sniall,  almost  completely  covered  by  the  colnmn  ;    forming 
the  bottom  part  of  the  concavity,  of  which  the  basals  constitute  the  sides, 
and  the  radial."?  with  large  interradial  plates  between  them  form  the    rim 
of  an  inverted  cono  on  which  the  remainder  of  the  calyv   rests.     IJadials 
longer  than  wide,  considerably  larger   than    the    eostals.     'I'he   interradial 
plates  large  and  covered  with  a  sharp  node.     Costals  hexagonal  and  hepta- 
gonal.     Distichals  two  in  the  calyx,  smaller  than  the  costals,  and  abont  as 
wide  as  long.     Arm  openings  of  the  same  ray  widely  apart,  separated  by 
two  or  three  intcrdistichals.     Arms  pendent,  slender,  branching,  and  with 
long  pinnules;  there  being  six  nltimate  arms  to  each  arm  opening.     Caly- 
clne  appendages  in  ten  pairs,  di,sposed  interradially ;  those  of  adjoining  rays 
in  sutnral  contact  to  about  12  mm.  from  the  calyx,  when  the  pairs  separate, 
and  the  two  tubes  take  a  sharp  outward  turn,  so  that  their  tips  meet  with 
those  of  adjacent  pairs.     Each  tube   is  composed  of  three  rows  of  plates 
longitudinally  arranged,  two  of  them  occupying  the  ventral,  the  third  the 
dorsal  side,  so  that  there  are   six  rows  for  the  distance  to  which  they  are 
united.     The  tubes  generally  branch  once  or  twice;  they  are  long,   and 
taper   gradually  to   their   tips.     Interbrachials  arranged   longitudinally   in 
three  series  of  plates  of  nearly  equal  size  ;  the  anal  side  not  distinct.     Vent- 
ral disk  low-hemispherical,  almost  flat,  the  plates  highly  convex,  tho,se  form- 
ing the  interradial  depressions  .somewhat  smaller.     Orals  a  little  larger  than 
the  other  di.«<k   plates,  and   rather  irregular  in  their   arrangement.     Anus 


(1-^ 


N 


240 


TIIK  C'UINOIDKA  CAMKUATA   OK    NOUTll    AMKKICA. 


rtliglitly  I'xcuntrip,  forming  ft  niiDple  opening  through  thu  tcgnien,  and  in 
nioxt  of  tiio  Hpi'i'iuions  covered  by  a  2'iii/ytrrits  njitihihru  Hall.  Culunin 
rounil  and  nitlior  ntotit. 

Ifiirizon  mill  LuntHlii  — Keokuk  group;  C'rawfoidsvilK',  Ind. ;  Hardin 
Co.,  Ky. ;  and  Kookuk,  Iowa. 

7///>t'  in  the  Lyon  rolleelion. 

/tiiiiiirh.  —  Tiii.s  Hpeeie.H  \x  Lyon  and  C'a.'^seduy'H  type  of  the  genuM  (/oiii- 
iinUroidocriiiiix, 


OilbertsoorinuB  dispansus  w.  mid  Sr.  (nov.  sp.). 

I'/>itr  X  r.  Fl</.s.  J,i,  f>,  r,  d. 

Sjn.  doiiiim/ei-riihrriiiiiK  /yiNiiiuHi  —  8.  A.  Mil,Lt:H  i   Oi'iil.  Surv.  Illiiiiiis,  Hull.  3,  p.  55,  rintp  4,  Kip.  ►. 

Of  the  typo  of  (,'i/f>irf>imr!iiits  htherosiw,  hut  a  sninllor  Hpecies,  the  nrnm  less 
iiumorons,  mid  the  oalycine  appendages  proportionally  larger.  Calyx  noine- 
wlmt  deprcHsed,  wider  than  high,  truncated  nt  the  bottom,  the  median 
portions  deeply  excavated.  PlateH  convex  except  the  radials,  which  are 
extended  into  elongate  nodes  or  obtuse  spines  directed  oblirpiely  downward. 

Infral)asals  small,  placed  at  the  bottom  of  the  concavity,  and  almost 
covered  by  the  column.  Ihisals  rather  small  for  the  genus;  their  distal  ends 
cur>ing  upwards  and  forming  together  with  the  median  portions  of  the 
radials  a  rim  upon  which  the  calyx  rests,  while  the  lower  portions  of  those 
l)Iati'.s  are  involved  in  the  concavity.  Radials  very  large,  more  than  twice 
as  largo  as  the  costal.s.  Cosfals  and  distichals  of  nearly  the  same  ."i/e. 
slightly  projecting  over  the  plates  of  the  interradial  and  interdistichid  areas. 
Interradiul  areas  composed  of  1,  3,  3,  2,  2  plates;  the  middle  one  of  the 
second  and  thinl  rows  a  little  larger,  and  raised  somewhat  above  the  level 
of  the  two  outer  ones;  the  anal  side  not  distinct.  Interdistichals  three, 
longitudinally  arranged.  Tegmen  flat,  with  five  deep  interradial  depres- 
sions, of  which  the  posterior  one  is  twice  as  large  as  the  others ;  all  of  them 
oval  in  outliiu',  and  surrounded  by  a  series  of  nodose  pieces.  The  anal  open- 
ing occupies  the  inner  end  of  the  larger  depression,  and  in  perfect  specimens 
appears  to  be  closed  by  a  pyramid  of  numerous  very  nunnte  pieces.  The 
smaller  depressions  are  paved  by  fom'  or  five  larger  plates  of  irregular  form. 
The  appendages  are  given  off  in  pairs  from  the  calyx,  being  for  (|uite 
a  distance  laterally  connected  ;  they  are  very  large,  slightly  pendent,  and 
each  pair  is  composed  of  six  longitudinal  rows  of  transverse,  slightly  nodose 


I! 


mioDocuiMn.E. 


941 


piocci,  nltorniituly  arrangud.  Tliey  Mf[mrate  iit  tlio  ciglilh  ur  toiitli  pluto, 
wlieii  tlioy  buiul  abruptly  outward  in  opixisito  diructious,  aud  earli  Minipio 
tubo  in  tliuncu  competed  ol'  tbrtiu  niwH  <jf  piucos.  Arum  wliort,  puiiduiit,  and 
recumbent;  tliey  aro  coinpo«ed  of  two  rowM  of  platuM,  and  |)innuIatL'd. 
Thoru  being  hIx  ariun  to  each  arm  oi)ening.  three  to  each  main  division, 
but  rarely  more  tiian  three  aro  exposed  to  view,  the  otherM  being  eoviMed  by 
the  appundagefl. 

Jlorixon  ami  Lomiiti/.  —  Keoicuk  group;  Indian  Creok,  Moutgoniory  Co., 
Ind.,  where  it  has  been  found  in  splendid  preservation. 

Ti/pea  in  the  collection  of  Wachsiuuth  and  Si)riuger. 

Oilbertsoorinus  obovatus  ^W.r.K  and  Woutmk.v. 
P/ute  X  VII.  J'^fjs.  4,t.  b. 

ISflO.     Oonin.ffi'roiilorriiiiis  nf/or/i/'i.'i—Mr.r...   (viul  Woutiikn  ;   I'mcreit.  Aciul.   Nul.  Sci.  I'liiln.,  p.  7fl  j  nml 

1H7;|,  (Icnl,  ll,'|).  llliniHs,  Vol.   V,     p.  W\.   ridtl'  4,  Fi,lt    0. 

19S1.     OUaeriimt  ohuealm — \V.  nnJ  Sp. ;  I..  'iKiiiii  l'Mln'ocr.,  I'l.  II.,  p.  rfl'J. 

Calyx  nrn-shapod;  basal  concavity  deep,  bit  narrower  than  in  any  of  the 
other  specicH ;  the  sides  of  the  donsal  cup  convex,  con.stricted  at  tiie  arm 
bases;  greatest  width  across  the  second  C'-ntals;  voi  .ul  disk  perfectly  flat. 
Plates  without  ornamentation,  strongly  convex,  and  .  i'  ather  uniform  si/e. 

Infrabasals  small,  forming  together  with  the  lower  part  of  the  basals 
an  inverted  cup.  IJa.sals  larger  than  aii)  »ii'i  r  plates  of  the  .  lyx,  bending 
abruptly  upwards  and  exposing  two  tlii  ds  c '  their  surfaces  in  a  A\\\i  view. 
Radials  a  little  longer  than  wide,  slightly  larger  than  the  costals,  the  ;  vi  (• 
faces  distinctly  angular;  the  interradial  jdates  considerably  smaller.  i)is- 
tichals  two,  larger  than  the  adjoining  intt  rbrachials ;  the  second  smaller 
than  the  first.  Arm  openings  proportionally  small,  at  the  bottom  of  a 
shallow  pit.  Calycino  appendages  continent  at  the  proximal  end,  and 
interradially  disjiosed.  Each  pair,  before  separation  takes  place,  is  composed 
of  six  rows  of  plates,  and  each  tubo  pierced  by  a  moderately  large  central 
canal.  Length  of  appendages  unknown,  as  is  also  the  form  and  construction 
of  the  arms.  Interradial  areas  elliptical,  arched  by  the  distichals  and  the 
plates  supporting  the  ap,,  u'^^ges ;  they  aro  composed  of  about  thirteen 
plates;  arranged:  1,  3,  3,  J  .,  or  I,  3,  3,  2,  2,  with  slight  variations  at  the 
anal  side.  Interdistichals  six  to  eight,  the  first  touching  the  axillary  distichal. 
Plates  of  the  ventral  di-k  rather  large  and  strongly  convex;  the  interradial 
depressions  small,  ei-bracing  only  one  or  two  pieces.    Orals  not  distinct  from 

81 


r 


M 


Ml 


242 


TIIlv  CKIXOIUEA  CAMKRATA  OF  NOKTII  AMKUICA. 


'II 


ill,' 


'ill 


the  other  plates.  Anal  opening  alinost  central.  Column  rounil,  filling 
nearly  the  whole  width  of  the  basal  concavity ;  axial  canal  small  and  pent- 
angular. 

Ilurizon  and  LocuUlij.  —  Highest  part  of  the  Upper  Burlington  limestone, 
Burlington  and  Pleasant  Grove,  Iowa.     Rare. 

TijiK  in  the  Museum  of  Comparative  Zoology,  Cambridge. 

llonnrhs.  —  In  this  and  the  two  preceding  species,  which  were  the  last  sur- 
vivors of  the  genus,  the  individual  tubes  arc  constructed  of  three  rowt. 
of  plates  instead  of  a  single  one  as  in  all  others.  This  species,  however, 
differs  essentially  from  all  others  in  the  form  of  the  calyx.  While  in  G. 
tiihei'osiis  and  similar  forms  the  ba.«als  form  the  sides  of  the  lower  concavity, 
they  are  placed  in  G.  obomtm  at  the  sides  of  the  dorsal  cup,  which  is 
decidedly  convex  in  the  latter,  but  flat  or  even  concave  in  the  former. 

Oilbertsoorinus  typus  (\\\\-\.). 
Plate  XIV.  Fiys.  I,  2,  3,  and  Flute  XVII.  Figs.  7a,  b. 

1859.     Tremaloeri/ma  fypiit  —  Hau-;  Siip|)l.  Geol.  Ucp.  Imvn,  p.  73. 

il872.     Giliir/ioiriiiHn  {Tiri,ialocriiiii.i)  h/iiim—  IIai.i,;  Hull.  Museum  Nat.  Hist.,  Tlatc  0,  Fi'd-  13. 
1S?3.     0'iiiiiinliT(iiitiirriiiii.i  li/pus  —  Mkkk  aud  Woutiikn;  (Icol.  Hop.  llliuoi.s,  Vol.  V.,  p.  391), 
18S1.     onucriiim  /,i/iiu.i  —  W.  and  Sr, ;  lievisioii  I'alavior,,  I't.  II„  p,  219. 
13S9.     Guiiidsti'roiilucrliHis  ti/pii* —  S.  A.  Millkk  ;  Norlli  Aiiicr,  Geol.  and  I'iila'ont.,  p.  250. 
Sjii.  Trciiialofriiiini  iiii)iil!ulu.i  IIai.i,  ;  .Suppl.  Ge(il,  Hep,  Iowa,  A'ol.  I,  p.  7'i, 

Calyx  broadly  concave  at  the  base,  somewhat  inflated  at  the  middle, 
contracted  near  the  top,  spreading  above  into  a  projecting  rim  around  the 
upper  margin.  Ventral  disk  low-hemispherical  or  .^lightly  convex.  Basals, 
radial.s,  and  interndials  produced  into  sharp  central  .«pines  or  elongate 
nodes;  all  other  plates  convex  and  .slightly  tumi*^!. 

Infrabasals  comparatively  large,  forming  a  pentagon,  of  which  the  greater 
part  is  exposed  beyond  the  column.  Basals  very  large,  curving  so  that  the 
lower  halves  of  the  plates  rest  within  the  columnar  concavity,  the  upper 
forming  a  part  of  the  lateral  walls  of  the  dorsal  c\ip ;  their  spines  directed 
downward,  while  those  of  the  other  plates  are  directed  outward.  Radials 
much  larger  than  the  costals :  the  interradials  one  half  smaller,  but  larger 
than  the  interbrachials.  First  distichal  smaller  than  the  second,  the  latter 
higher  and  axillary,  supporting  two  arms,  which  branch  from  the  third 
palmar,  and  again  on  one  side  from  the  third  post-palmar,  making  a  cluster 
of  arms  to  each  opening.  Arms  pendent,  long  and  delicate,  uniscrial  to  the 
last  bifurcation,  when  the  plates  become  cuneate  and  interlock.     Pinnules 


\f[ 


RIIODOCRIXID^E. 


243 


well  proportioned.  Tlie  calycine  appendngcs  pendent,  unusually  stout  and 
lonjf,  and  composed  of  cylindrical  joints  whose  apposed  i'accs  are  striated. 
The  joints  grow  longer  as  they  decrease  in  width,  and  at  the  end  of  the 
tubes  are  twice  as  long  as  wide  ;  they  are  thicker  in  the  middle  than  at  the 
ends,  and  the  median  part  is  marivcd  by  a  transverse  row  of  little  nodes. 
The  tubes  of  adjacent  ambulacra  are  united  to  their  sixth  or  seventh  joints, 
and  the  plates  meet  alternately  by  a  zigzag  suture.  Interbrachials :  3,  3,  3, 
3,  2  —  exceptionally  two  in  the  first  row  —  the  upper  row  abutting  against 
the  appendages.  The  anal  side  has  an  additional  plate  in  the  second  row. 
Interdisticlials  about  six  to  each  area.  Ventral  disk  pentangular  in  outline, 
with  five  interradial  depressions;  the  posterior  one,  which  contains  the  anus, 
larger;  the  plates  of  nearly  uniform  size  and  all  convex.  Orals  uiuletermin- 
able.  Anus  more  excentric  than  in  the  preceding  species.  Column  large 
and  round ;  the  nodal  joints  higher  and  wider,  tlieir  edges,  like  those  of 
the  intervening  joints,  slightly  rounded.     Axial  canal  sharply  stellate. 

Horizon  and  Locality.  —  Upper  IJurlington  limestone,  and  Burlington  and 
Keokuk  Transition  bed;  Burlington  and  Pleasant  Grove,  Iowa. 

T^pc  in  the  Worthen  collection. 

licmarls.  —  We  regard  Hall's  Trcmalncrinus  jm/nllatiis  as  a  mere  varia- 
tion of  this  species ;  the  spines  of  the  plates  being  shorter  and  the  calyx  more 
robust.  In  the  Revision,  Part  II.,  p.  210,  we  erroneously  placed  it  as  a 
synonym  under  Gilbcrtsocrbms  ttibcrciilusiis. 


Oilbertsoorinus  tuberculosus  (Hall). 
Plate  XVI I.  Fifjs.  Su,  b,  c. 

1859.     Tremaiorriiiiis  liibrrciilosiis  —  IIali.  ;  Siippl.  Iowa  Geol.  Hop.,  Vol..  I.,  p.  7j. 
1881.     OUiieriiiiis  lubcffiilosiin  Vi.  i.iid  Sp. ;  Uuvisiou  I'alivncr.,  I'nrt  II.,  )).  219. 
1S89.     Guiiin-i/i'ruiihrriiius  liibprriilu.iiis  —  S.  A.  Millku  ;  Xciitli  Aiiicr.  I'alii'oiit.,  250. 

In  the  form  of  calyx  and  arrangement  of  plates,  this  species  closely 
resembles  the  preceding  one,  but  the  arms  are  erect  inste.ad  of  pendent,  the 
appendages  much  shorter,  and  they  taper  rapidly  to  a  point.  Plates  strongly 
convex  or  slightly  nodose,  the  surfaces  smooth. 

Infrabasals  placed  at  the  bottom  of  a  shallow  concavity,  which  is  formed 
by  the  lower  half  of  the  basals,  the  upper  half  curving  upwards,  and  taking 
part  in  the  lateral  walls  of  the  calyx.  Basals  and  radials  considerably  larger 
than  any  of  the  succeeding  plates.  Costals  fully  one  half  smaller  than  the 
radials.   Distichals  4X10;  the  two  lower,  which  are  placed  in  the  calyx,  as  large 


M 


''^  III 

ft       ' 

'A 


I; 


244 


THE  CRINOIUEA  CAMKUATA  OK  NOKTII  AMERICA. 


as  the  costiils ;  the  two  upper  shorter  and  free.  There  are  four  arms  to  each 
arm  opening,  the  upper  bifurcation  taking  place  from  the  third  plate.  Arms 
rather  stout  and  long  for  the  genus ;  they  are  erect,  biserial  from  the  last 
axillary,  and  have  closely  set  pinnules.  Calycine  appendages  small  and  short ; 
directed  outward,  almost  at  right  angles  to  the  calyx.  They  are  composed 
of  single  joints,  of  which  the  four  or  five  proximal  ones  of  adjoining  rays  are 
truncated  laterally  on  apposed  sides,  and  connected  with  one  another  by 
rigid  suture ;  tlie  plates  interlocking.  After  separating,  the  two  tubes  taper 
rapidly,  and  terminate  at  the  end  of  the  fourth  or  fifth  joint.  The  nvnnbcr 
and  arrangement  of  the  interradial  plates  is  quite  variable ;  but  in  the  major- 
ity of  specimens  the  plate  between  the  radials  is  succeeded  by  three  plates; 
some,  however,  have  but  two,  except  at  the  anal  side  which  always  has 
three ;  there  are  two  or  three  in  the  next  row,  exceptionally  four  at  the  anal 
side.  Interdistichals  five  to  six.  Ventral  disk  low-convex,  with  well  defined 
interradial  pits;  the  posterior  one  larger,  and  containing  the  anus.  Column 
round ;  axial  canal  sharply  stellate. 

Horizon  and  LocaUty.  —  Upper  Burlington  limestone  ;  Burlington,  Iowa. 

Ti/pc  in  the  Museum  of  Comparative  Zoology,  Cambridge. 

Remarlis.  — Readily  distinguished  by  the  upright  arms,  and  short,  rapidly 
tapering  tubes. 

Oilbertsocrinus  reticulatus  (Hall). 

Flute  XVII.  Figs,  la,  b. 

ISOO.     TremotorriiiKii  reddiliiliis  —  II.vLi, ;  Dcscr.  New  Spec.  Criu.,  p.  9:  also  Boston  Journ.  Xat.  Hist., 

Vol.  VII.,  p.  3ii5. 
T8S1.     Ollarriiius  reiicii/u/u.i—W.  i\ml  Sp. ;  Rcvisiou  Palieocr.,  Part  11.,  p.  219. 
ISS'J.     Goiiiasteroidocrinus  reticiihi'its  —  S.  A.  JIilleu;  North  Aiucr.  Gcol.  and  Palicont.,  p.  250. 

Calyx  small  compared  with  the  preceding  species,  about  as  wide  as  liigh ; 
dorsal  cup  urn-shaped  with  convex  sides  and  a  wide  and  deep  concavity 
at  the  bottom ;  ventral  disk  almost  flat.  Plates  slightly  convex,  their  sur- 
faces marked  by  a  series  of  obscure  ridges,  radiating  from  the  centre  of  the 
plates  to  adjoining  ones.  The  ridges  follow  the  rays,  and  those  passing 
from  the  radials  to  the  hasals  are  stronger  antl  somewhat  higher ;  the  latter 
producing  around  the  basal  concavity  at  the  bottom  of  the  calyx  the  well 
defined  figure  of  a  pentagon  with  convex  sides. 

Infrabasals  forming  a  pentangular  disk,  of  which  the  angles  project  quite 
plainly  beyond  the  column.  Basals  largo,  their  upper  ends  curving  abruptly 
upwards,  the  lower  portions  of  the  plates  to  two  thirds  their  length,  together 


RIIODOCRINIDiE. 


245 


With  the  infrabasals  and  the  extreme  ends  of  the  radials,  forming  a  wide  and 
deep  inverted  basin.  Radials  as  large  as  the  basals,  a  little  longer  than 
wide.  Costals  nearly  one  half  smaller  than  the  radiuln,  both  of  the  same  size, 
and  higher  than  wide.  Distichals  2  X  2  in  the  calyx,  nearly  as  large  as  the 
ouitals ;  the  upper  excavated  to  form  the  arm  openings,  whicli  are  largo  and 
circular.  Appendages  composed  of  single  circular  joints;  the  proximal  ones 
in  contact  laterally.  Their  length  and  the  construction  of  the  arms  un- 
known. Interradial  spaces  wide,  elliptical ;  the  plates  between  the  radials 
smaller  than  the  costals;  the  interbrachials  arranged  in  rows  of  three  and 
two  plates,  which  decrease  but  little  in  size  upwards.  Tiie  anal  interradius 
apparently  not  distinct.  Interdistichals  one.  Column  round,  composed 
near  the  calyx  of  very  short  joints;  the  edges  of  the  nodal  ones  knife-like. 

Ilnrhnn  and  Locality. — Lower  Burlington  limestone;  Burlington,  Iowa, 
and  Sedalia,  Mo. 

TijiK  in  the  Museum  of  Comparative  Zoology,  Cambridge. 

Gilbertsocrinus  flscellus  (^Fekk  ami  Wohth.). 


1S60. 
1S()5. 
1866. 
18S1. 
1839. 


Plate  XVII.  Figs.  2a,  b,  c,  d. 

Tmiia(ofri«ii.f/fef/lit'i—yiEEK  and  Wnnxn. ;  Proceed.  Acad.  Nnt.  Sri.  Thilii.,  p.  383. 
Gilbert-wcrinii-i  {Gmiiiisteroidocr^  fi!ir(>llus  —  Meek  ami  Worth.  ;  il)i(l.,  p.  167. 
Gilljerhorriiiiis  Jisn-llux  —  .Meek  mid  Worth.  ;  Gcol.  Urp.  Illinois,  Vol.  II.,  p.  2^2,  Tlate  15,  Fig.  5. 
OUacrimisJhcrllm —  W.  and  Si'.  ;  Revisir'i  Palieocr.,  Part  II.,  p.  219. 
OonimteroiilocrinHsf.icellH.i  —  S.  A.  JIii.ler;  North  Anicr.  Palicont.,  ji.  2.")0. 


A  small  species,  smaller  even  than  G.  rctkulatiif^,  which  it  resembles 
in  general  form ;  but  the  sides  of  the  calyx  are  straighter,  the  basal  con- 
cavity narrower,  and  the  ridges  upon  the  plates  less  con.-<picuous. 

Infrabasals  very  small,  covered  by  the  column.  Basals  hidden  almost 
completely  within  the  lower  cavity,  so  that  the  radials  and  first  intcrradials 
form  the  lower  ring  of  plates  visible  from  a  side  view.  Costals  as  long  as 
wide,  and  but  little  smaller  than  the  radials.  The  second  distichals  support 
the  free  arms,  of  which  the  first  joint  is  short  and  quadrangular.  The  arm 
openings  of  the  same  ray  are  placed  closer  together  tlian  in  any  other 
American  species,  and  the  tubes  bordering  the  anal  interradius  are  simple, 
with  several  interradial  plates  interposed  between  them;  while  those  of 
the  other  sides,  on  the  contrary,  are  united  in  pairs.  Nothing  further  is 
known  of  the  appendages  and  arms.  Interradial  areas  arranged  :  1,  3,  3,  3, 
3,  2;  the  lower  plate  somewhat  larger.     The  anal  side  gonerallv  has  five 


I 


r 


! 


J 


fl 


•  ' 


II I 


246 


THE   CKINOIDEA   CAMERATA   OF   NOUTII   AMEHICA. 


pliiU's  in  the  tliiril,  fourth,  mid  fifth  rows,  and  two  small  plates  above.  Intor- 
diriticiial  areas  composed  of  a  rather  large  plate,  succeeded  by  four  or  five 
smaller  ones.  Ventral  disk  almost  flat,  with  deep  interradial  depressions. 
Some  of  the  plates  are  larger  and  more  convex,  but  none  of  them  are  refer- 
aI)lo  to  orals.  Anus  subcentral,  on  top  of  a  small  protuberance.  CoUnnn 
unknown. 

Jloriziiii  ami  Lorulif//.  — Lower  Burlington  limestone  ;  Burlington,  Iowa. 

Tijjjc  in  the  Museum  of  Comparative  Zoology,  Cambridge. 


Gilbertsoorinus  tenuiradiatus  (^l.  and  w.). 
Plate  XVII.  Fifj.  3. 

ISCiO.     Ooni.tsteroidocriiiiis  IfniiintilUitus  —  Mir.K  niul  Woiitiib.v;  Proccrd.  Aond.  Xnt.  Sci.  Pliiln.,  p.  "J- 
l>>(li.     (loiiiiixlrniiilurriiiini  Iciiiiiriidiatus —  .\1ekk  and  WoiiTUEN  ;  Cn'ol  .Kcp.  Illinois,  Vol.  V.,  j).  ShU,  I'liilc 

ll.l-iK.l. 
1S81.     Otlih-riiius  l,;iiiii;iili,ilm  —  \\.  mid  Sr. ;  Rrvision  raliiwr.,  Part  H.,  p.  219. 
ISS'J.     Ouiiiiisleroiilucrinus  leiiiiirii</i(i/u.i  —  S.  A.  Millkb;  Norlli  Aiiier.  Ge(jl.  mid  Palocont.,  p.  250. 

The  two  specimens  before  us  are  considerably  cru.xhed,  and  their  general 
form  and  the  arrangement  of  the  plates  cannot  be  accurately  determined. 
It  is  a  larger  species  than  the  two  preceding  ones,  with  which  it  is  found 
associated,  and  which  it  resembles  in  the  delicacy  of  the  plates ;  but  in  other 
respects  it  is  more  like  G.  (y/;/^s,  of  a  higher  horizon.  The  surface  of  the 
plates  is  marked  l>y  a  series  of  elevation.s,  radiating  from  the  middle  of  the 
plates  to  adjoining  ones,  whi('%  however,  are  not  ornamented  ridges,  but  are 
produced  by  a  folding  of  the  plates.  The  basal  concavity  is  quite  shallow, 
and  composed  almost  exclusively  of  the  infrabasals. 

Basals  large,  curving  upwards  and  inwards,  their  upper  lateral  faces 
longer  than  the  corresponding  lower  ones;  they  arc  extended  into  a  sharp, 
slender  spine  rising  from  the  centre  of  the  plates,  unlike  the  case  of  G.  tiijius, 
in  whieii  the  .spines  cover  the  whole  surface  of  the  plate.  Radials  very 
large,  and  mounted  with  similar  spines  as  the  basals.  Arms  given  olT  from 
the  .second  distichals ;  their  structure  unknown.  Calycine  appendages  very 
long,  and  tapering  but  slightly ;  their  joints  are  strictly  cylindrical  and 
devoid  of  ornamentation  ;  they  are  arranged  interradiall}-  in  pairs,  and  tlio^e 
of  each  pair  are  connected  laterally  by  zigzag  sutiu'cs  to  the  fourth  or  fifth 
joint,  when  they  become  free  and  diverge  in  opposite  direction."?.  The 
number  of  arms  and  the  number  and  arrangement  of  interradial  and  inter- 
distichal  plates  cannot  be  ascertained  in  tlio  specimens. 


RIIODOCHIMD.K. 


247 


ir<>rlzon  and  Larnli/i/.  —  Lower  Burlington  limestone;  Burlington,  lowix. 

7'ijpe  in  the  Museum  of  Comi)iirative  Zoology,  Cambridge. 

lionarks.  —  This  species  is  distinguished  from  G.  Ii/pnn  by  the  form  of 
the  spines  on  the  bnsals  and  radials,  the  thinness  and  delicacy  as  well  as  the 
folding  of  the  plates,  and  by  the  cylindrical  form  and  smoothness  of  their 
appendages. 

Oilbertsoorinus  spinigerus  (,iiali.). 

Plate  X  V.  Flijs.  o'a,  h,  c. 

1Sfi2.  Trnmlorriintf  .yi!ii!fffnis~U\u.;  l.jth  Kcp.  N.  Y.  State  Cal).  Xat,  Tlisl.,  p.  128. 

ISfifl,  Giwiaaternidocriiiiin  uphiii/rriis  —  Mkkk  niiil  WoiiTil.;  (icol.  Surv.  llliiKiis,  Vol.  II.,  p.  222. 

ISri.  Gilbfrlmriiim  (TrcmiilijcriiiK^)  yiiiiii/i'ni.i —  Hall;  New  Voik  Stale  Mus. Kut.  liibt.,  Bull.  I.,  Tlate 

Irt,  Fiu.  9  (privately  (listribiitcd). 

1S77.  Goiiiaalfrniilm-riiius.iiiiiiiiirru<,  —  S.  A.  JIn.LERj  Cat.  .Xiiior.  I'aln'oz.  Foss.,  p.  SO. 

I'-Sl.  OlliicriiiM  xfiiinijfrm  —  W.  and  Si'.  ;  KivUiou  I'alicocr.,  I'arl  II.,  p.  219. 

1SS9.  GoniiisleroiJoeriinis  spiniyeiun  —  S.  A.  MiLLEB;  North  Aiiicr.  (Icol.  and  Pala'niit.,  p.  2.')0. 

A  small  species.  Calyx  widest  acro.ss  the  radials,  somewhat  constricted 
at  the  arm  bases,  expanding  at  the  upper  nuirgin.  The  rays  marked  by 
broad,  rounded  ridges  proceeding  to  the  arm  openings,  and  giving  to  the 
section  acro.ss  the  co.stals  a  pentangular,  and  across  the  distichals  a  deeagoiuil 
outline ;  while  the  .section  at  the  margin  of  the  disk,  where  the  appendages 
meet  in  ptiirs,  a.sstimes  again  a  pentangular  outline,  but  the  angles  ai-e  inter- 
radial  instead  of  radial.  Tl>e  plates  without  ornamentation,  but  the  radials, 
first  costals  and  first  interradials  are  extended  into  sharp  nodes  or  small 
.spines.  Basal  concavity  deep  and  wide,  involving  the  infrabasals,  ba.sals,  and 
portions  of  the  radials  and  interradials. 

Infnil)asals  comparatively  large,  forming  a  regidar  pentagon.  Basals 
large  their  upper  sloping  faces  twice  as  long  as  the  corresponding  lower 
ones  ;  broadly  truncate  above.  Radials  of  nearly  the  same  size  as  the  basals, 
and  deeply  wedged  in  between  them.  First  costals  considerably  larger  than 
the  second,  and  but  little  smaller  than  the  radials.  Distichals  quite  small, 
especially  the  second,  which  is  deeply  excavated  to  form  the  arm  openings. 
Cidycine  tubes  confluent  at  four  sides,  those  facing  the  anal  side  simple  and 
separated  by  anal  plates.  The  appendages  are  short,  directed  almost  horizon- 
tally, and  are  composed  of  joints  about  as  long  as  wide.  Anns  erect,  rather 
stout,  the  plates  cuneate ;  they  start  in  pairs  from  the  calyx,  branch  on  the 
fifth  plate,  and  again  on  the  eighth.  The  plates  of  the  interraditd  spaces 
small,  except  the  first  which  is  very  large ;  it  is  followed  by  3,  3,  3,  3,  and 
two  plates.     Interdistichals   three  or  more.     Ventral  di.sk  flat,  with  deep 


^ 


< 


248 


TIIK   ClUXOIDKA   CAMKRATA   01"   NORTH  AJIKRICA. 


intcrradiul  depressions,  surroundud  by  smidl  nodose  plates  of  rather  irregular 
nrrangeiueiit.     Oral.s  tuberculous;  anus  excentric. 

llvrizon  and  Lwaliii/.  —  llaniilton  group ;  Ontario  Co.,  and  Thedford, 
Ontario. 

Ti/2}es  in  the  New  York  State  Cabinet  of  Natural  History  at  Albany,  and 
in  the  Canada  L  rvey  Museum  at  Ottawa. 

THYLACOCRINUS  Oehleut. 

1S7S.     OniLEiiT;  Extr.  dii  null.  Soc.  Gool.  dc  Finiice  (sur.  3)  Tome  VIL,  p.  578. 

ISi'J.     ZiTTKi. ;   Ilamll).  d.  I'liia'diit.,  Vol.  1.,  p.  375. 

18S1.    W,  mid  Si'. ;  licvisiou  I'ldicocr.,  rait  II.,  p.  207  (Proceed.  Acad.  Nat.  Sci.,  Pliilu.,  p.  381). 

Calyx  large,  plates  convex;  anal  interradius  distinct  from  the  others; 
arms  arranged  in  groups  of  four  or  more.  Infrabasals  five,  small.  Ba.xals 
five,  hei)tagoual ;  their  upper  faces  truncated,  and  each  plate  supporting  an 
interradiid.  Radials  followed  by  two  costals,  and  these  by  2X2  distichals, 
which  in  turn  support  within  the  calyx  several  brachials  of  a  third,  and 
sometimes  of  a  fourth  order.  Arms  heavy,  long,  simple  throughout,  and 
biserial.  Interbrachials  numerous,  arranged  longitudinally  in  series  of  two 
or  three,  with  additional  plates  at  the  anal  side.  Interdistichals  very  numer- 
OU.S,  in  rows  of  one  or  two ;  interpalmars  al.^o  represented.  Construction  of 
the  tegmon  and  position  of  the  anus  imknown.  Column,  so  far  as  observed, 
pentangular  with  re-entering  angles. 

Distribution.  —  Devonian;  France,  and  Hamilton  group;  Western  New 
York. 

T///IC  of  the  genus.  —  Tliijlacocrinus  Vannioti  Oehlert. 

Jiitnarks. —  T/u/ldrncrinus  differs  from  lihodocrhius  in  having  interdis- 
tichals and  interpalmars ;  the  former  being  very  rarely,  the  latter  never, 
preserved  in  that  genus.  It  also  differs  in  the  arrangement  of  the  plates 
of  the  anal  side,  in  having  four  or  more  primary  arms  to  the  ray  in  place  of 
two,  and  in  that  the  arms  are  large  and  simple  throughout. 

Thylacocrinus  Clarkei  w.  and  Sr.  (nov.  spec). 

Plate  XIII.  FIrjs.  ]  la,  h. 

Calyx  apparently  globidar  ;  the  plates  very  gradually  and  uniformly'  de- 
creasing in  size  upward.s.  Infrabasals  .small,  and  forniing  a  pentagon  with  the 
points  of  the  angles  f^lightly  projecting  beyond  the  column;  column  attach- 


RIIODOCRIXID.E. 


249 


mont  stclliforni,  somewhat  concave,  the  margin  surrounded  hy  concentric  stria) 
as  in  Jurassic  Pentacrinidtv.  Basals  large,  shghtly  curving  upward.  Radials 
as  wide  as  liigh,  of  the  same  size  as  the  costals.  Disticlials  2x2,  a  little 
shorter  tjian  the  radials.  The  four  lower  palniars  form  part  of  the  calyx, 
the  upper  are  free ;  the  fi.xed  plates  consideral)ly  highest,  hut  decreasing  in 
height  upwards;  the  three  proximal  arm  plates  suh(iuadrangular,  the  suc- 
ceeding ones  gradually  turning  from  cuneate  into  bi.serial,  meeting  laterally 
by  a  zigzag  suture.  Arms  four  to  oach  ray,  simple  throughout,  rather  strong 
at  the  bases  ;  their  length  unknown.  Interbrachials  :  1,  2,  3,  2,  etc.,  some- 
what smaller  than  the  adjoining  brachials.  Anal  intcrradius  wider,  with 
three  plates  in  the  second,  and  four  in  the  third  row.  Interdistichals  in 
about  six  ranges,  arranged  in  pairs  from  the  first  plate  up.  lnter])almars 
three  to  four,  arranged  longitudinally  in  single  file.  Ventral  disk  and 
anal  opening  unknown.  Column  pentangular  with  re-entering  angles  near 
the  calyx ;  the  joints  of  nearly  eijual  width ;  the  salient  angles  of  the  nodal 
ones  bearing  a  small  tubercle. 

Horizon  and  Locality/.  —  Hamilton  group ;  Canandaigua  Lake,  N.  Y. 

Ti/pc  in  the  New  York  State  Cabinet  of  Natural  History  at  Albany. 

licmnrh.  —  The  species  is  described  from  a  somewhat  crushed  specimen, 
formerly  in  the  collection  of  Prof.  John  M.  Clarke  of  Albany,  N.  Y.,  in  whose 
honor  the  specific  name  is  given. 


r 


,  1 


DIABOLOCRINUS  W.  and  Sp.  (nov.  geu.). 

(Aia/3o\o«,  the  devil ;  xpivov,  a  lily). 

Syn.  Motloerinui  (in  pnrt)  —  White,  ISSO;  Proceed.  Nntiniinl  Musoiim,  Vol.  II.,  p.  230. 

SjMi.  h/i-locniiii.1  (ill  iiart)  —  S.  A.  MiLi.Eli,  1SS2;  .lourii.  Cineiii.  Soe.  Ni\t.  llist.,  Vol.  V.,  p.  117. 

Sjii.  .Irrhfurriiiiis  (in  purl)—  \\.  niid  Sp,,  ISS.');  Proceed.  Acini.  Nut.  Sci.  Pliila.,  p.  3-20. 

Svii.  Arch.nii-riiiim  (in  part)  —  W.  aii[i  Sr.,  1S85  ;  Revision  Pala'oer.,  Part  III.,  ]).  9S. 

Syn.  ArcliMcriaus  (hi  part)  —  S.  A.  Millkk,  ISS'J;  N.  A.  Gcol.  niid  Palu.'ont.,  p.  225. 

Calyx  deprcs.sed  globular,  with  a  wide  and  deep  concavity  at  the  bottom, 
involving  the  infrabasals  and  large  portions  of  the  ba.sals.  Infrabasals  five, 
small,  but  projecting  beyond  the  column.  Basals  large,  elongate ;  their 
upper  hiilf  directed  horizontally  or  bending  upwards;  the  upper  faces  broadly 
truncated.  Tladials  not  in  lateral  contact,  being  separated  from  each  other 
by  one  or  more  plates,  which  rest  upon  the  basals.  Costals  two.  Arms  two 
to  the  ra}'.  free  from  the  first  or  second  distichals  ;  their  structure  unknown. 
Arm  openings  very  large,  directed  obliquely  upward,  and  arranged  in  groups. 

as 


H 


or. 


50 


THE  CRIXOIDEA    CAMERATA   OF  NORTH   AMERICA. 


Inturradial  spaces  wide,  composed  throiigliout  of  large  plates,  wliich  connect 
with  tlie  disk  plates,  or,  properly  speaking,  pass  into  the  disk.  The  large 
plates  between  the  radials  arc  frequently  surrounded  by  small  supplementary 
or  secondary  pieces,  which  wholly  or  partly  isolate  them  from  the  basals, 
radials  and  costals.  The  second  range  of  interradials  consists  of  two,  excep- 
tionally three,  pieces,  the  third  of  three  ;  the  latter  foiming  part  of  the  upper 
margins  of  the  arm  openings.  The  anal  interradius,  which  is  wider  than  the 
others,  has  three  plates  in  the  second,  and  four  or  more  in  the  third  row. 
Ventral  disk  depressed  conical ;  composed  of  rather  large  plates,  none  of 
them  conforming  to  the  general  arrangement  of  orals,  which  are  probably 
unrepresented.  Anus  almost  central,  and  at  the  end  of  a  strong  tube. 
Column  round  or  indistinctly  pentangular,  with  a  large  pentalobate  canal. 

Dhtrihutlon.  —  The  three  species  herein  described  come  from  the  Trenton 
group  of  Eastern  Tennessee.  In  the  same  locality  we  found  a  fourth  species, 
but  none  of  the  specimens  so  fur  obtained  are  sulliciently  well  preserved  for 
description. 

Remarks.  —  We  make  our  DtahuJocrimcs  perpkxits  the  type  of  the  genus. 
Dtaholocrinus  has  closer  resemblance  to  Lyriocrinus  and  Archwocrixiis  than 
to  lihodocrinm,  but  is  readily  distinguished  from  both  of  them.  In  Lijriu- 
criinis  the  arm  facets  are  directed  strictly  upwards,  the  arms  are  single 
and  placed  in  a  straight  liqe  with  the  walls  of  the  dorsal  cup;  v'lile  in 
Dlaholocrinm  the  arms  were  apparently  given  off  as  armlets  from  tubular 
j)rolongations  of  the  calyx,  and  the  facets  are  directed  obliquely  outward. 
ArcliwucriHus  has  a  more  elongate  calyx,  the  disk  consists  of  minute  irregular 
pieces,  it  has  no  anal  tube,  and  never  supplementary  pieces  such  as  we  find 
in  D.  pcrpUxus.  The  latter  is  a  feature  that  reminds  us  of  Iktencr'r.uis,  Xmo- 
crinita,  and  Acrocrimts,  in  which  a  similar  intercalation  of  jilates  takes  place 
on  a  much  larger  scale. 


Diaboloorinus  perplezus  w.  and  Sr.  (nov.  spec). 
Plate  XI.  Figs,  la,  b. 

Length  of  calyx  as  compared  with  its  width  three  to  two;  pentangular 
across  the  arm  bases ;  the  dorsal  cup  more  than  twice  the  height  of  the 
tegmen  ;  basal  concavity  wide  and  moderately  deep,  involving  nearly  the 
whole  of  the  basals.  Plates  convex,  the  larger  ones  bearing  one  or  more 
conspicuous  nodes,  the  others  a  .single  central  one. 


RIIODOCRINID^E. 


261 


Infmbnsols  coinplotely  hidden  by  the  top  stem  joint,  nnsnls  large,  elon- 
gate, barely  seen  in  a  side  view,  longitudinally  grooved  nt  the  median  line, 
wiiich  gives  to  the  cavity  a  decidedly  pentangular  outline  ;  tlie  angles  of  tlie 
upper  face  truncated  for  the  reception  of  supplementary  pieces,  wliicli  in  this 
species  are  not  only  constantly  represented  but  quite  regular  in  their  arrange- 
nient.  Costals  less  than  half  the  size  of  the  radials.  Distichals  still  snuillcr 
and  free  above  the  first.  Arm  openings  in  pairs;  elongate.  Interradials 
1,  2,  3  in  the  dorsal  cup;  the  first,  which  is  nearly  as  large  as  the  basals, 
surrounded  variously  by  from  two  to  four  supplementary  pieces,  two  of  them 
abutting  against  the  radials  and  basals,  and  two  against  the  radials  and  first 
costals.  These  plates  vary  greatly  in  size,  being  in  some  specimens  very 
minute,  while  they  arc  comparatively  largo  in  others.  In  very  large  speci- 
mens, when  completely  developed,  the  first  regular  interradial  is  surrounded 
1)\-  six  plates  —  including  the  two  regular  interradials  of  the  second  row  — 
and  by  seven  plates  at  the  anal  side.  In  cases  in  which  the  supplementary 
pieces  are  small  and  imperfectly  developed,  the  first  interradials  touch  the 
radials  and  basals.  Tegmen  composed  of  rather  large  plates  without  any 
regidarity  in  their  arrangement;  the  interradial  portions  depressed,  those 
concealing  the  ambulacra  quite  prominent.  CoUnnn  small,  obtusely  pentan- 
gular; axial  canal  very  large. 

Horizon  and  Locality.  —  Trenton  group,  near  Knoxville,  Tenn. 

Tf/jjcs  in  the  collection  of  Wachsmuth  and  Springer. 


Diabolocrinus  vesperalis  (White). 
Plate  XL  Figs.  Ic,  d. 

1B80.     Rhoihcriims  tenperalia  —  Wiiitk;  Proceed.  U.  S.  Museum,  Vol.  II.,  p.  259. 

1S83.     Rlioiheriiim  rojuralis  —  AViiiTE  ;  Twelfth  Ann.  Rep.  U.  S.  Gcol.  Surv.  Terr.,  liy  Ilnydcii,  p.  l-.'9, 
Plate  35,  Figs,  in,  h. 
Syn.  Lifriorriiiiis  icii/p/i/h  —  S.  A.  MiLLEU  ;  \S^2  (not  Hull  1851),  Cincin.  Journ.  JCnt.  Hist.,  Vol. 

v.,  p.  117,  Plate  3,  Figs.  C,a,  h. 
Syu.  hyrioeriiius  inilptiis  —  S.  A.  MiM.ER;  ibid,  (privnte  cd.,  Explnimtion  of  plnlc). 
Syn.  Ji-c!iii<icriiiii!<  sctil/i/m  —  W.  itnd  Si'.  18'^5  ;  Revision  Paln'ocr.,  Piirt  III.,  |ip.  Ofi-OS. 
Syn.  Jichrrocrinm  sciilpliis  —  S.  A.  Mii.i.Eii,  1889;  North  Anier.  Geol.  nnd  Pala'ont.,  p.  225. 

Calyx  depressed  subglobose,  pentangular  across  the  arm  bases ;  the  basals 
to  one  third  their  length  forming  a  funnel-shaped  concavity,  of  which  the 
infrabasals  form  the  bottom  part.  Plates  but  very  slightly  convex,  densely 
covered  by  wrinkles  or  indistinct  striae. 

Infrabasals  invisible  beyond  the  column.   Basals  large,  elongate,  the  prox- 


H 


1 


r> 


262 


THK  CRlNOinKA   CAMKUATA   OK   XOUTII   AMERICA. 


! 
Ill 


imal  portions  concave;  tlio  distal  portions  of  tlio  plates  bending  upwards; 
the  faces  supporting  the  intcrradials  broadly  truncated.  Railials  sometimes 
Rnialler  than  l)asals  and  intcrradials,  their  lower  faeen  decidedly  angular. 
Costals  smaller  than  thurndials;  the  second  shorter  and  narrower  than  the 
first.  Distichals  to  the  height  of  the  second  plate  incorporated  into  the 
calyx,  tlie  succeeding  ones  free  ;  the  plates  siiort  nnd  semilunate.  Ueguliir 
intorradials :  1,  2,  3,  the  first  nearly  as  large  as  the  basals,  the  upper  ones 
considerably  smaller;  the  supplementary  pieces  irregularly  distributed  among 
the  interrays,  or  aksent  altogether.     Tegmen  as  in  the  preceding  species. 

Ilurtziin  and  Locallf//.  —  Same  as  last. 

'J'l/jx:  in  the  National  Museum  at  Washington. 

]iiiiiiir/,s.  This  form  was  descril)ed  by  White  in  1880  under  the  name 
of  li/i(iili>cn'iiiis  nsjnrd/is,  and  it  was  stated  that  the  specimen  probably  came 
from  the  coal  measures,  thirty  miles  west  of  Humboldt,  Kans.  S.  A.  Miller 
rcdeseribed  the  species  in  1882  as  Lijrioci'inm  scnlptm*  giving  "  Tennessee  " 
as  locality,  and  '"Niagara  group"  as  the  probal)le  hori/on.  The  specimens 
from  which  our  figures  are  made  were  collected  by  one  of  us  in  188.",  from 
rocks  of  the  Trenton  group  at  Knoxville,  Tenn.,  where  they  were  found 
associated  with  J/i/bvrn'inin  and  otiier  typical  Trenton  lornis.  We  have  com- 
pared these  specimens  carefully  with  White's  type  o£  JtlKiilorrinnn  I'csjtiraHs  in 
the  National  Museum,  and  also  with  Miller's  Lijiiocrinua  sciiJjitiis  in  his  own 
collection,  and  not  only  find  the  various  specimens  specifically  identical,  but 
think  it  most  proljabie  tiiat  they  ail  came  from  the  same  locality. 

Diabolocrinus  hieroglyphious  w.  ami  Sr.  (nov.  spec). 

PI  :/c  X.  FSf/s.  Sa,  h.  c. 

Calyx  globose  ;  basal  portions  deeply  depres.sed,  forming  a  narrow  fun- 
nel-shaped pit,  of  slightly  pentangular  outline,  which  enclo.ses  the  whole  of 
the  infraba.sals  and  one  fourth  of  the  ba.sals.  Arm  openings  directed  ob- 
liquely upwards,  and  invisible  in  a  dorsal  view.  Plates  of  the  donsal  cup 
covered  with  numerous  elongate  nodes,  of  irregular  form,  which  give  to 
the  surface  an  appearance  sugj.'estivo  of  being  densely  covered  with  hiero- 
glyi)liics.  The  rays  are  marked  by  consjjicuous  ridges  following  the  median 
line  of  the  plates,  and  similar  ridges  pass  out  from  the  centre  of  the  radials 

•  Tt  wns  described  in  the  .Iniinial  of  tlic  Ciiiciiinnfi  Society  under  tlie  imii.c  of  lyriurriiiua  sciilptilia  ; 
but  Stiller,  on  finding  the  nanie  preoccupied,  cimuged  it  in  his  private  edition  to  L.  tmt/ituf. 


IKfUDOCUlNID^K. 


2fi8 


to  ndjoininj,'  ImHiils,  tlio  latter  fonniii)^  upon  tlic  hiiiTih-o  ii  well  ili'liufil  fivc- 
myed  .star,  wIiomo  Niiliciit  angles  altoinatu  with  the  angles  of  the  hu.sal 
concavity. 

IntniltasulH  Hninll,  and  ahnont  completely  covered  hy  the  upper  joint  of 
the  column.  BasalH  largo,  elongate;  spread  out  horizontally,  except  their 
lower  ends,  which  form  the  sides  of  the  funnel-shaped  pit.  IJiidiaN  large, 
their  lower  faces  sharply  angular.  Costals  smaller  than  the  radials;  the 
second  considerahly  smaller  than  the  (irst.  Distiehal-i  free  from  the  second 
plate;  very  short.  Arm  structure  unknown.  Interhraehials  :  1,  •_».  ;.,  2.  1. 
with  variations  of  three  plates  in  the  second,  and  two  to  four  in  tiie  ihini 
ranges;  the  first  plate  large,  heing  next  to  the  ha.sals  the  largest  plate  of  tho 
calyx  ;  the  plates  of  the  .second  row  considerahly  Bmaller,  especiully  when 
there  arc  more  than  two  plates  in  that  row.  The  supplementary  interradials 
are  less  frequently  represented  than  in  the  preceding  species,  and  rarely  hy 
four  plates  to  tho  interray ;  hut  there  is  scarcely  a  specimen  in  which  there 
is  not  at  least  one  of  them  introduced  at  one  side.  The  plates  of  the  third 
row  arc  placed  between  the  arm  bases;  the  succeeding  ones  form  part  of  the 
ventral  disk.  The  anal  side  is  wider  and  the  jjlatcs  more  numerous ;  there 
being  three  or  four  in  the  second  row,  and  four  or  more  in  the  Micceeding 
ones.  Ventral  disk  aImo.st  as  high  as  tho  dorsal  cup;  composed  of  rather 
large  convex  plates  of  nearly  uniform  size.  Orals  cannot  bo  identified,  the 
whole  ventral  pavement  consisting  of  the  same  kind  of  irregular!}-  arranged 
plates.  Anus  nearly  central,  extended  into  a  strong  tiilie.  Column  near 
the  calyx  apparently  slightly  pentangular;  central  canal  very  large  and 
pontalobato. 

Horizon  and  Lornlltij.  —  Trenton  group  ;  near  Knoxville,  Tenn. 

Ty^wH  in  the  collection  of  Wachsmuth  and  Springer. 

liniiarl's.  —  This  species  is  distinguished  from  tiic  preceding  one  by  the 
different  form  of  the  calyx,  the  peculiar  s'tyle  of  ornamentation,  and  by  the 
irregularity  in  the  distribution  of  supplementary  pieces  in  the  interradiul 
series. 

ARCHiEOCRINUS  W.  and  Sp. 

18S1.  W.  nnd  Sp.  ;  Revision  Pnlivorr.,  I'aii  IF.,  p.  1^9;  iiImi  rnicccd.  Aend.  \ot.  Sci.  I'liila ,  p.  .'1(13. 

18S5.  AV.  nnd  Sp.  ;  Hi^visicin  I'ldicdpr.,  Part  III.,  p.  90;  I'rnpccd.  Acad.  Nat.  Soi.  I'liila.,  p.  IflS. 

18S3.  S.  A.  Mii.i.Kfi ;  Jmini.  rinciii.  S<ic.  Nat.  Hist.,  Vdl.  VI.,  |i.  217. 

1SS9.  S.  A.  MiLLEu;  N.  Ainer.  Gcdl.  and  Palipont.,  p.  2ii. 

Calyx  large,  obconical  or  subovate  ;  plates  smooth  or  variously  orna- 
mented ;    those  in  a  radial   direction   marked  along  their  median    line  by 


I 


(M 


loi 


Tin:  riMNolDK.V  CAMKKATA   OF  NOKTII    AMKlMf'A. 


oliHciirt',  lliittiiicil  ridgi'H,  wliicli  j^row  moro  conHpioiioux  on  n|i|mi:icliiiij^ 
tliu  anii.«.  liilViiliaMiilH  ;<iiiull,  iiuclv  cNtciiiling  ho^uiid  tlio  ooliiiiin,  nmi 
rL'.>tliiig,  ii«  II  rule,  wiiliiri  a  CDiu-avity  forinril  by  tliu  lower  part  of  lliii 
l)a-'al.M.  Ilasalx  lie|ila^'oiial,  their  upper  I'aees  Iriiiieated.  KadiaLi  in  tliroo 
of  llie  rays  peiilagoiial,  in  tiie  two  posterior  oiieM  frecpiently  liexiij^oiial. 
When  lliuro  uru  no  pahnurrf  the  throe  to  hIx  lowur  dintiehals  tnkf  part  in  iho 
eidyx,  and  ihu  nufeeeding  ones  arc  freo  urn»  phiten.  Arum  chort.  xleiider, 
liraiiehinj,' ;  eoinpoM'tl  of  two  rows  of  ciineifonn  pieees,  alternately  arranjred 
and  inieiioeivin^.  lnlerrii<lial  areas  cuiiHtrncted  of  nnnuTons  platen;  the 
platu  lii'iween  the  radialn,  whieii  is  nineh  1ar^a>r  than  the  othorn,  is  t'ollowod 
ut  tho  regular  sides  by  two  interbraehials  in  tlic  Rocond  row,  nt  the  nnal  side 
by  three,  but  there  is  no  median  ridge  or  cuntiiiiious  row  of  nnal  pintes. 
Tile  upper  interbraehials  Cdnnect  inipereeptibly  with  the  plates  of  the  disk. 
Interdi.'^ticlial.s  always  represi'iiled.  \'entral  disk,  as  observed  in  .{.(hxlilmitiis, 
ooui|)o.si'd  III'  small  irregular  pieces,  which  close  over  the  ainl>ulaera,  except 
ni'ar  the  outer  margin  of  the  integument,  where  their  covering  pieces  arc 
exposed.  Colunm  round,  the  edges  of  the  nodal  joints  largely  projecting 
over  the  iuternodal  om-s  ;  axial  cannl  large,  peiitalobate. 

DislrlliiiHiiii,  —  I'robably  restricted  to  the  Trenton  group  of  Americn. 

Tij/H'  of  the  genus:  ArcJidom'tnis  lticinii>mi>i  (Billings). 

lictiiitrks. — ArvliaocrhiKH  has  close  nllinities  with  Jihoihcriiivs,  and  it  is 
somewhat  dillieult  to  point  out  tho  structural  difTerence-s,  The  calyx  of  the 
former  is  relatively  larger,  the  arnm  shorter,  and  it  has  but  two  interbraeh- 
ials in  the  seconil  row  ;  while  lilimhirriiniK,  ns  a  rule,  has  three  plates  in  the 
sicond  and  all  succeeding  rows  ;  and  the  anal  interradius  very  often  has  tlio 
same  arrangement  of  plates  ns  the  others. 

(jlilj)ti>rr!iius  iiiarijiiiatus  Hillings,  which  in  1881  we  placed  under  Arrhtro- 
(•r!/iv»,  proves  to  be  a  monocyclic  form,  nnd  will  have  to  be  referred  back  to 
(rli/j)t()rriiui.i  as  a  somewhat  aberrant  type.  Whether  lihodocrltiiis  axjwrnfiis 
Billings  belongs  here,  caimot  be  ascertained  from  tho  imperfect  state  of  the 
specimen.  Li/rloerlnits  nculptus  S.  A.  Miller  {Archaocrliius  sriilj)fi(>i  W.  &  Sp.) 
is  n  synonym  of  lihoihcrinus  ve»pcralis  White,  which  has  been  placed  nnder 
the  genus  Diahohcrinus. 


:*l 


■|i 


uiioixkiumd.t:. 


255 


Arobnoorlnuii  laounoiui  «  !'iui,inuii). 
i'lati:  X.  Fi<j.  1. 

1837.     (ll^filiicriHiit  liicHuiinii — lllM.lN<i»;    (ii'ul    Ur|i.  CuiiimI.i  (lti|i.  nf  I'lnKi),  |>.  lidl,  iiKm  iliiil.  ISJO, 

DtLMuli!  IV.,  |>.  ftl,  I'lalr  H,  FiKs.  11  n-f. 
ISSl.     .iivhinii-riau)  liirMiioiiiii  —  \\ .  ami  Nl'  ;    llrvi'iiiin  I'lilifncr.,  I'liil  II  ,  p.  I',)ll. 

Till'  only  known  Hpocinion  is  Hotnowliiif  criiHlit'd,  luul  its  cxiut  (nrin  ciin- 
not  111'  iiMCi'itaini'd,  hut  it  was  piolmlily  miligl()l)()f<i'.  'I'lie  niciliaii  line  of  tlii 
rnys  is  followed  by  lidj^'i'M,  wliicli  j,mo\v  qiiito  pioiiiiiifiit  ii|i(in  tin-  ilistjclinls. 
and  till!  smface  of  tlio  pliitcH  is  coniplotcly  covered  l»y  small  riiji<iM'  iiit.^i  and 
wiinklcM. 

Iiifral)ii.«<alH  very  niinnto,  not  visilde  from  a  Hide  vit'W.  Ha.xalx  nmiHnally 
larjjo,  the  liirgest  |ilate.><  of  the  ealyx  ;  tlu'ir  truncated  iipper  nide  very  wide. 
Kadials  .slij^htly  Niiialler  than  the  Ita.xalH,  the  two  fafin^'  the  posterior  side  he|v 
tngonal,  the  others  pentajjonal,  all  Himrply  nn;,'nlar  helow.  Costals  rather 
nmall.  The  three  lower  dintiehalH  take  part  in  the  I'ahx  ;  they  are  small 
and  curved  like  free  arm  plates.  Arms  ten  at  their  oriirin,  rounded,  laflier 
delicate,  hifiircating  once  or  oftener,  the  branches  diveijrent,  and  cninposed 
of  short  interlocking  pieces.  Interbrachiali  large  ;  those  between  the  radials, 
which  are  almo.st  as  large  as  the  ba.sals,  ri.se  to  the  middle  of  the  .second 
disfichals,  and  are  followed  by  two  plates  in  the  second  range,  and  others 
above  ;  anal  side  wider,  plates  arranged  :  1,  ."),  4,  etc.  Column  roiiiid,  tap- 
ering considerably  downward  ;  the  nodal  joints  very  high,  even  those  next 
the  calyx,  which  are  twice  as  wide  as  the  intervening  ones,  and  thick  and 
rounded  at  the  edges;  the  internodul  joints  comparatively  short.  At  six  cm. 
from  the  calyx  the  internodes  contain  five  joint.s,  and  this  number  upparcntly 
does  not  increase  in  the  lower  part  of  the  stem. 

Iloi'hon  mid  LocnUtij.  —  Upper  part  of  Trenton  group;  Ottawa.  Canada.  - 

Tiii)c  in  the  Canada  Survey  Mu.scuni  at  Ottawa. 


»l 


I    •■ 


Archseocrinus  pyriformis  Billikos. 
Phde  X.  Figs.  Sa,  h. 

1S57.     Thi/mnorriiim  (RMorrinim)  pyri/ormit  —  'R.  Hii.i.iNos  ;  Oco].  Ticp,  Tanndn  (Rrp.  of  rrogr.),  p.  20:1 
1S59.     ll/iii(/iii;-iiiiiii  iii/ri/hniii.i  —  K.  Uil.l.lNiis;  ibid.,  Dfcadi-  IV,,  p.  (ll,  I'lali'  (i,  Fiifs.  \(i-i/. 
1S81.     Ari'liirni'riim.i  pi/riformin  —  W.  mid  Sp. ;  lievlsion  Pnlirorr.,  I'arl  II.,  p.  lOH. 

A  largo  species.     Calyx  obconical  or  pyriform  ;  one  fourth  higher  than 
wide;  greatest  width  across  the  second  disticlmls,  slightly  contractinjr  r.liove. 


H 


lioi, 


TllK   tlMNOIDKA   CAJIKKATA   OK    NOUTII   AMI'.HICA. 


Suil'aco  111"  pliitcs  Miiuolli  (ir  finely  j;nuuilosc  ;  tlio   radial  plates  .soniewhnt 
elevated  aloiiy  their  median  lines;  sutures  distinct,  but  not  grooved. 

Infrabusals  laryer  tiian  in  any  other  known  spceies  of  this  genus,  and 
plainly  visible  from  a  ;  ide  view,  rorining  ii  shallow  cup.  Uasals  large,  a  little 
higher  than  wide,  upper  face  narrowly  truncated.  ISadials  and  co.stals  of 
similar  size,  the  lormer  pentagonal,  the  two  .osvals  hexagonal.  e.Ncept  in 
the  posteiior  rays  in  which  the  second  is  heptagtmal.  Distiehals  to  the 
height  o^'  the  sixth  plato  incorporated  into  the  calyx,  gradmilly  decreasing 
in  height  ;  the  first  as  large  as  the  second  iMterl)rachials,  the  upper  one 
resemliiing  a  good  sized  arm  plate.  Arms  short,  delicate,  twice  bifurcat- 
ing; couiposei.  from  their  ba.ses  up  of  small  triangular  interlocking  jiieces. 
Interbrachials :  1.  'J,  2,  2,  etc.,  rarely  1,  2,  3,  ?>,  the  lower  plate  heptagonal, 
larger  than  the  radials;  at  the  anal  side  there  are  three  plates  in  the  second 
and  all  succeeding  rows.  Interdistichals  nine  or  more,  rather  large.  Struc- 
ture of  ventral  disk  and  anus  not  know.i  Colmnn  circular,  slightly  tapering  ; 
in  the  upi»er  part  of  the  stem  the  nodal  joints  project,  but  further  down  have 
the  same  size  as  the  others. 
-~—  Jliiriiiiii  (iiiil  Lucdli/i/. —  Trenton  limestone;  Montreal,  Canada. 

'J't/jiiK  ill  the  Canada  Survey  ^luseum  at  Ottawa. 


1S.-.7. 
18S1. 


AroheeocrinuB  mic^o^aBali8  Hillisos. 
Plate  X.  Fli/x.  Ja,  h,  c. 

Thy«iiiniTi»iiii  (R/iD'locriiiin)  inifrubnmtlis  —  K.  Hii.i.iNfiS  ;   Giol.  Iti'p.  Canada  (Rep.  of  Proirr.) 

p   M\;  ;il>c)  ilii.l.,  Decade  IV.,  p.  (W,  I'lale  fi,  \'\f.  2. 
Airh,rwriiiu.t  mii-ruhimalis  —  \V.  ami  Sr.;  Itevision  I'aliEOCr.,  Part  11.,  p.  I'JO. 


Smaller  than  the  preceding  siiecios,  the  arms  proportionally  longer. 
Calyx  oliconical,  truncated  at  the  lower  end,  sides  .slightly-  convex.  Surface 
beaut  if  nlly  ornamented  with  parallel,  radiating  stritv,  proceeding  from  tho 
middle  of  the  plates  to  adjoining  ones,  and  broad,  rounded  ridge.«,  starting 
from  the  middle  of  the  radials  and  passing  up  the  costals  and  distiehals  into 
the  free  arms. 

Infraba.sds  minute,  forming  a  pentagon,  which  rests  within  the  ba.sil  con- 
cavity and  is  covered  by  the  colunni.  IJasals  large,  heptagonal,  niore  than 
two  thiids  of  the  plates  visible  from  a  side  view,  the  lower  end  bent  inward 
and  forming,  togrihcr  with  the  infrabasals,  a  good  sized  concavity,  with  a 
thickened  rim  arc  nid  tho  edge;  tho  upper  faces  narrowly  truncated.  Radials 
as  large  wa  the  ba.sals, distinctly  angular  below;  the  costals  somewhat  smaller. 


it 


lUIODOCRINin.K. 


257 


HI  s 


Tlie  lower  diHtichals  (o  the  nmnbcr  of  «evoii  or  ciglit  take  pa  in  the  calyx; 
they  decrease  rapidly  in  size,  the  lower  one  being  comparatively  large,  bnt 
the  ♦'Muth  is  but  little  larger  than  the  free  plates ;  the  plates  above  are  tri- 
angular and  interlock.  Arms  long,  rather  stout  at  their  bases,  but  tapering 
gradually  to  the  tips  where  they  are  quite  thin  ;  they  bifincate  twice  or 
oftener,  and  are  composed  of  two  rows  of  plates  witli  parallel  faces.  Regu- 
lar interl»rachials :  1,  2,  o,  o,  followed  by  numerous  smaller  plates;  the 
anal  side  has  1,  .'),  3,  4,  t/r.  Of  interdistichals  as  many  as  fourteen  pieces 
have  been  ol)st'rvcd,  tiie  lower  one  resting  upon  the  first  distichais.  Con- 
struction of  the  ventral  disk  and  form  and  position  of  the  anal  opening 
unknown.  Oolumn  roimd,  tajjcring  downward;  the  upper  part  composed 
of  alternately  large  and  small  joints  with  angular  edges;  but  at  about  three 
inches  from  tiie  calyx  the  internodal  joints  reach  the  width  and  height  of 
the  nodal  ones,  and  the  edges  lose  their  angidarity. 

lliivi.viiii  mid  LiwalUii.  —  Trenton  limestone  ;  Ottawa,  Canada. 

The  figured  specimens  are  in  the  collection  of  Mr.  John  Stewart  of 
Ottawa.     Tyiic  in  the  Geological  Survey  Museum  at  Ottawa. 

ArchSDOcrinus  desideratus  w.  «.  i!ii,i.iN(is. 

riaU:  X.  FiffH.  4a,  b. 

]>«S:i.     Vi.  n.  Illll.ixr.s;  Trans.  Field  Xntiir.  f'luii,  Oltawii  No.  fl. 
1SS5.     \\.  aiul  Si'.;  lt.\isi(iii  I'aliL'oer.,  I'arl  1 1 1  ,  p.  'JS. 

A  rather  lar'^e  species.  Calyx  depressed  globose  ;  basal  portions  deeply 
depressed,  forming  a  broad  funnel-shaped  pit,  much  wider  than  the  ciioum- 
terence  of  tiie  stem,  and  deep  enough  to  contain  five  or  six  stem  joints. 
Plates  convex,  without  ornamentation  or  other  markings,  except  ol)scure 
elevations  —  a  kind  of  broad,  roiindod  ridges  —  following  the  median  line 
of  the  rays,  and  branching  to  the  ba.sals. 

Infiabasals  small,  hidden  by  the  column.  Basals  large,  twice  as  long  as 
wide;  the  lower  half  of  the  plates  forming  the  sides  of  the  ba.sil  pit;  the 
upper  Iialv<>s.  which  l)end  abruptly  upward  and  outward,  occupy  the  sides 
of  the  cup.  Iiadials  pentagonal,  almost  as  long  as  wide,  their  lower  faces 
forming  a  sharp  angle,  which  extends  down  to  the  margin  of  the  basal 
concavity.  First  costals  hexagonal,  as  wide  as  the  radials,  but  shorter ;  the 
second  .shorter  and  narrower  than  the  first.  Distichais  1x2,  all  incor])c'ated 
into  the  calyx,  and  comparatively  small ;  they  are  rounded  exteriorly,  and 

3.1 


I   I 


258 


THE  CRIXOIDKA  CAMERATA  OF  NORTH  AMERICA. 


I       ! 


tlio  two  scries  of  the  siiine  ray  are  so  nearly  in  contact  as  to  leave  but  a  nar- 
row space  for  the  insertion  of  interdistichals.  First  distichals  somewhat 
longer  than  the  succeeding  ones,  wiiich  are  (|uite  short;  tiie  fourtii  is  axil- 
lary, giving  off  to  the  outer  sides  a  row  of  pahnars,  whieii  are  free  from  the 
third  or  fourth  plate;  to  the  inner  side  two  jjalmars,  of  which  the  upper 
is  axillary,  and  supports  two  arms,  making  three  arms  to  each  side  of  the 
ray.  Arms  subcylindrical,  stout,  very  little  tapering;  composed  at  their 
bases  of  a  few  (juadrangular  pieces,  followed  by  euneate  ones,  which  deeply 
interlock.  Pinnules  strong,  given  off  nearly  at  right  angles,  and  composed 
of  short  joints;  the  first  very  much  stouter  than  the  others,  given  off  from 
the  second  distichals,  anil  wholly  or  partly  incorporated  into  the  calyx, 
Interradial  spaces  wide,  the  upper  portions  rather  deeply  depressed.  The 
plates  of  the  two  lower  ranges  verj-  large,  the  first  being  the  largest  plate  in 
the  calyx.  There  are  probably  five  or  six  rows  above,  but  the  number 
of  plates  in  each  row  is  extremely  variable;  the  third  contains  variously 
from  three  to  five  plates  at  the  regular  sides,  and  from  four  to  six  at  the 
anal  side;  the  fourtii  row  has  as  many  as  eight  in  some  specimens.  The 
first  plate  of  the  anal  side  is  somewhat  larger  than  those  of  the  regular 
sides;  it  is  octagonal,  its  upper  angle  being  slightly  truncated  for  the  recep- 
tion of  a  narrow  anal  plate,  which  is  placed  between  two  interbiachials. 
Interdistichals  from  one  to  three,  longitudinally  arranged.  Ventral  disk 
rather  Hat.  composed  of  veiy  small  irregular  pieces;  the  aiuljulacri)  subtog- 
minal,  except  near  the  arm  bases,  but  the  course  of  the  ambulacra  is  marked 
by  high  ridges  wliich  diverge  to  the  arms,  anil  form  deep  depressions  all 
along  the  interambulacral  spaces.  Orals  apparently  unrepresented,  the  sum- 
mit being  covered  by  similar  .small  plates  to  the  rest  of  the  disk.  Anal 
opening  subcentral,  at  the  top  of  a  well  defined  protuberance.  Cohunn 
round  ;  axial  canal  large,  pentalobate,  the  outer  ends  of  tlie  lobes  widest 
and  truncated. 

-      Jloiivon  ami  Locaiitif. —  Trenton  limestone  ;  Ottawa,  Canada. 
Ti/pi's  in  the  collection  of  Mr.  Walter  R.  Billings,  Ottawa. 

RHAPHANOCRINUS  AV.  .iml  Sp. 

18S5.     \y.  nml  Sp.  ;  Revision,  Part  III.,  p.  9«  (I'locLfil.  .\rail.  Nat.  Sci.  riiiln.,  p.  320). 
18S7,     Okim.kIiT;   Aim.  dcs  Spi.  Ciro!.,  T.inir  XIX.,  I'lalp  I  ,  Fii:s.  10,  11. 
1889.     S.  A.  .Mii.i.KK;  NdiIIi  Aiiicr.  (Icul.  and  I'alii'oiil.,  p.  277. 

Sy,   <:iKj!'m-riiiiia  (in  pall)  —  Wau  OTT  ;  1'<8H,  Xi'W  Spec.  Foss.  of  the  Trenton  group  of  New  York, 

p.  2  (At)slr.  rrnin  tin-  .'(.'>( li  Urp.  New  York  State  Museum  Xat.  Hist.), 
Sjn.  ffA/;)/oi'/7>«t  (ill  part) —  S.   A.   MiLi.KK;  Juiirn.  Ciiiciii.  Sue.  Nat.  Ilisl.,  Vol.  V.,  p.  37,  and 
ibid.,  1SS.3,  Vol.  VI.,  p.  221. 


IIIIODOCRINID^E. 


lo9 


Allied  to  Archwocri'iuis,  but  arms  iiniserial  and  not  bifurcating.  Radial 
ridges  generally  well  developed.  Infnibasals  sinall,  not  vi.sible  from  a  side 
view,  and  generally  completely  bidden  by  tbe  column.  IJasals  largo,  bexa- 
gonal,  tbe  upper  face  truncated  for  tbe  reception  of  tbe  first  interradial.s. 
Hadials  and  second  costals  of  .similar  form,  but  tbe  former  angular  below, 
tbe  latter  angular  above.  Arms  ten  to  twenty,  free  from  tbe  di.sticlial.s  or 
palmars  according  to  .species;  tbey  are  .xtout,  long,  .simple,  and  composed 
of  quadrangular  pieces  witb  strong  pinnules.  InterbracbiaLs  and  interdis- 
ticbals  numerous.  Structure  of  ventral  disk,  and  form  of  tbe  anus  unknown. 
Column  large  and  round. 

Dltslri(iiill'ii).  —  IJotb  American  species  arc  from  tbe  Lower  Silurian.  Oob- 
lert  described  a  species  from  France  under  tbe  name  Ii/ta/>/i(aiorrini(s  U'ur/is- 
iiiit/hl,  wbicb  came  fiom  tbe  "  Devonien  inferieur,"  but  tbis  is  apparently 
not  a  typical  form. 

T>/j)e  of  tbe  genus:  JiJuijihanocrimis  subnodosus. 


\U 


Rhapbanocrinus  subnodosus  (Wamott). 
rtnh:  XI.  F!,j.  2. 

ISS:!.     (7/yp/orriiius  {'■)  Stt/moilosus  —  Vt'\ur,TT,  3jlli   Uc|i.   N,  York  Sliitc  Mils.  X.it.  Hist.,  p.  20S,  TLilc 

17,  I'll,'.  3. 
1SS5.     IHiip/iunorrimis  .lubnitiloriin  —  W.  niid  Si'.;  Hcvisinii  I'ala-ocr.,  Part  III.,  p.  90. 

Calyx  of  medium  size,  obconical ;  interradial  areas  depressed.  Hadial 
ridges  well  defined  and  marked  by  a  small  node  in  tbe  centre  of  eacb  [date  ; 
tbey  pass  down  to  tbe  middle  of  tbe  radials,  wlierc  tbey  meet  witb  similar 
ridges  from  tbe  two  ailjoining  basals.  Tbe  iuterradials  luive  also  a  central 
node,  from  wbicb  obscure  ridges  pass  out  to  tbe  margins  of  tbe  plates,  wbere 
tliev  meet  witb  ridges  from  adjacent  plates. 

Infrabasals  completely  covered  by  tbe  colimin.  Basals  very  largo,  fully 
as  bigb  as  wide,  sligbtly  truncate  above.  IJadials  beptagoual,  larger  tliiin 
eitber  one  of  tbe  costals.  decidedly  angular  below.  Arms  ten,  ratber  stout, 
simple,  tbe  lower  plates  incorporated  into  tbe  calyx,  tbe  second  and  all  suc- 
ceeding ones  piniude-bcaring ;  tbey  are  composed  tbrougbout  of  compara- 
tively long,  quadrangular  joints,  witb  stout  pinnules,  placed  wide  apart. 
Interradials :  1,  "J,  3,  3,  and  two  or  more  rows  above.  Interdisticbals  :  1,  2. 
Xotbing  is  known  of  tbe  ventral  disk  or  of  tbe  anal  opening.  Column 
round,  very  large. 


M 


■g— ^■«^--- 


260 


THK   {  HIXOIDKA   CAMKRATA   OK   NOIMII    AMKUK   V. 


II(iri::oii  dud  Localihj.  —  Upper  portion  of  the  Trenton  liniostone;  Trenton 
FaUs,  N.  Y. 

Tijpc  in  tlie  Miiwuni  of  Conipurativo  Zolilogy,  Cambridge. 

Rhaphanoorinus  soulptus  (Mn.t.Kit). 
Plate  X.  Fi(j.  3. 

1882.     GlnitnrrinHi  sfHlplm—^.  A.  Mii.i.i  ii ;  Joiini.  C'iiicin.  Sic.  Nnt.  Hist.,  Vol.  V.,  p.  37,  riiilp  I., 

Fi^'.  i. 
lSS:t.     di/iilui-riiiHii  m-iiliitii'  —  ^.   A.  .Mll.I.Kli;  iliiii  ,  Vol.  VI.,  p.  22t. 
l^S."l,     (lli/iiliicriiius  nfiiliiliin —  W.  ami  Sr. ;   Kcvisioii  I'lilirnrr.  I'arl  III.,  p.  1111. 
ISS',1.     (llj/iilofi-iiiii.i  nfiiliiliis  —  S.  A.  Mii.i.Ku;  N.  Aimr.  (Ii'ol.  and  i'lila'cuil.,  p.  218. 

Oiilyx  .suhglobo.'^o ;  interriuliiil  .spaces  deeply  depres.^ed,  especially  the 
upper  portion ;  section  across  the  .second  costals  sharply  pentagonal,  across 
tiie  distichals  decagonal.  Radial  ridges  quite  prominent,  angular,  stronger 
toward  the  sntures  than  at  the  median  portion  of  the  plates.  Somewhat 
smaller  ridges  pass  into  the  hasals,  forming  deep  triangular  depressions  along 
their  sides.  Other  riilges  run  from  the  radials  and  brachials  to  the  inter- 
radial  plates,  dividing  the  whole  surface  into  munerous  impressed  triangular 
areas. 

Infraba.sals  almost  covered  by  the  column.  Basals  of  medium  size,  pro- 
duced into  angular  processes,  which  jioint  downward  for  a  short  distance 
idong  the  sides  of  the  upper  stem  joints.  Radials  and  costals  al)()iit  as  wide 
as  long.  Distichals  three,  almost  as  large  as  the  costals.  Tlie  iilates  of  the 
tiiii'd  order  su])port  the  arms,  of  which  there  are  twenty;  they  are  long, 
gradually  tapering,  and  composed  of  (piadrangular  joints  which  become 
slightly  cuneate  in  the  upper  parts  of  tiie  arms.  The  four  to  five  lower 
joints,  which  are  ccm.siderably  the  largest  and  shaqdy  angular  on  the  out- 
side, take  part  in  the  calyx ;  the  succeeding  ones  are  free,  much  shorter,  and 
rounded.  Pinnules  long  and  slender.  Interradial  spaces  deeply  de))res.-e(l 
between  the  disticiials ;  the  j)lates  arranged:  1, 'J,  .'],.').  t/c  The  anal  side, 
which  is  a  little  wider,  has  a  few  additional  plates,  but  no  anal  ridge.  Inter- 
distichals:  1,  2,  1.  Structure  of  ventral  di.sk  imknown.  Colunni  roinid, 
slightly  tapering  downwards,  the  nodal  joints,  near  the  calyx,  wider  and 
considerably  longer  than  the  intervening  ones,  but  at  two  inches  below  the 
latter  reach  almost  the  same  size. 

Jfi>i-!.-(>ii  mid  Liividitij.  —  Upper  part  of  the  Hudson  River  group ;  Warren 
Co.,  Ohio. 

7'  I  cs  in  the  collection  of  I.  II.  Harris,  Esq.,  at  Waynesville,  O. 


m 


RHOnOCIUNIDvE. 


261 


licmrirks.  —  Ii/tajiJianocrlitiis  f<ni/j)tus  Avas  ilcscribcd  as  monocyclic,  and 
referred  by  S.  A.  Miller  to  Gljjitiwrhut^.  The  inlViibasals  arc  only  seen 
as  small  dots  around  the  column.  The  species  is  readily  distinguished  from 
allied  forms  by  having  knife-like  ridges  upon  the  fixed  brachials;  while  the 
back  of  the  free  brachials  is  perfectly  rouiul. 

LTRIOCRINUS  nur.. 

\V,i.     Ham,;  firol.  Rrp.  N.  Y,  rnliwiuldliK.v,  V.il.  II.,  p.  197. 

1857.     I'liTKT  i  Triiilr  dc  ralrmit.,  V<il.  I\'.,  p.  'AiW. 

l.sn-i.     l)r.iAUiii.N  aiul  lliri:;  lllsl.  Niitiir.  clis  /nDph.  Ktliliiod.,  p.  1  111. 

180(1.     SiiiMAiin;  Tiiins.  .\ciiil.  Sci.  fS(.  Lniiis,  Vul.  II.,  p.  li/'J. 

1807.     IIai.i.;  :JiiiIi  Krp.  N.  Y.  Mali'  Call.  Nat.  Hist.,  p.  Si."). 

1879.     IIai.i.;  is\\\  Hep.  N.  Y.  State  Mus.  Nat.  IliM.  (iil.  i).  p.  l.'iO. 

1881.     W.  and  Sr.  ;   UcvisiDii  I'ahi-iicr.,  Tart  II.,  p.  -MW  (I'riKTcd.  Aiad.  Nat.  Sci.  I'liil'i.,  p.  .'i?;). 

18S1.     Mali.;  lltli  .\iiii.  Hep.  Indiana  l>v  ('ull.l.  p.  iiCO. 

1889.     S.  X.  Mii.i.Kii;  Ninth  Ann'r.  (Irc.l.  and  ralinrnt.,  p.  a.'jS. 

Svn.  Mnrniiplocriiiim  (udt  I'liillips)  IIai.i.;  isi:i,  (iced,  till  Distr.  New  Yiirk,  p.  11  I. 

Svii.  It/iuilucniiHn  (mil  .MiIUt)  IIai.i.,  ISOIl;  Trans.  Alliany  liisl.,  p.  I'JS. 

Calyx  deprcssed-globoso,  more  or  less  flattened  to  the  middle  of  the 
radiiils;  symmetry  almost  perfectly  pentamermis;  plates  heavy,  their  s^lrfaee.■^ 
smooth  or  finely  granular;  ventral  disk  not  rising  above  the  dor-sul  cup;  arm 
openings  directed  upwards,  placed  at  the  ujipcr  margin  of  the  disk.  Infra- 
basals  five,  very  ,«uiall,  abruptly  and  deeply  depressed  and  concealed  by  the 
column.  Ba.sals  five,  of  uniform  size,  either  all  hexagonal  and  supporting 
upon  the  truncate  upper  face  the  first  interradial  plate ;  or  (piite  frequently 
one  or  more  of  them  hexagonal,  and  angular  at  the  top.  Costals  two;  large. 
Two  of  the  distichals  enclosed  in  the  ciilyx.  Arms  two  to  the  ray,  rising  in 
a  straight  lino  with  the  sides  of  the  ctdyx;  simple,  .strong,  biserial,  two  of  the 
interlocking  plates  fi'ei|nently  in  the  calyx.  Inlerbraehials  four,  in  three 
rows;  1,  2,  i.  Anal  side  generally  not  distinet,  but  exceptionally  it  lias 
a  special  anal  plate  in  the  second  row.  I)i-k  Hat,  somewhat  depressed  in  the 
interradial  regions;  composed  of  a  great  number  of  .xlightl}'  convex,  delicate 
pieces,  iiud  well  defnu'd  orals.  Anus  subceiilrid,  probably  tit  the  end  of  a 
small  tiilie. 

Column  of  less  tluin  lueiliuiu  size,  round;  axial  canal  small. 

Disfrihiitioii.  —  Upper  Silurian.     America  ami  iMirope. 

T///H'  of  the  genus  :   /,i/n'"rriiiits  (hicti/hn'  Iltill. 

Jicinnrka.  —  'i'lie  name  /.>/n'"('riiins  was  proposed  I'ov  t\  species  from  the 
Niagara  group  of  Lockport.  which  had  been  described  under  J/arsnpiorniiux, 


m 


c 


262 


TIIK   CHIXOIDKA  CAMKHATA   OK   NOIiril   AMKKIC'A. 


niul  was  Hupiiosed  to  liiivo  but  one  ling  of  pliitcs  bciieiith  the  riidials. 
Anotlier  spt'cios,  cloarly  of  the  wmu'  goiui.x,  wii.s  iiltoiwurils  rtfenocl  l)y  Hall 
to  lihvdocr'um.  In  the  construction  of  the  calyx  L^/riucrinn.  apiJioaclics 
Ji'i/iiilumiwx,  wliicli,  liowuvcr,  differs  very  e.x.senlially  in  the  arm  structure. 
S.  A.  Miller's  L//rmrmis  ncit/plus,  which  in  the  Hcvi-ion,  Part  II.,  we  placed 
j)rovisionalIy  under  Arc/uewriiiHs,  belongs  to  JJiiiMicrluiis,  and  is  identical 
witli   J).  viK/icni/in  White. 

In  this  genus  we  have  a  good  illustration  of  the  exceptional  variation 
from  the  characteristics  of  a  group,  which  maybe  met  with  among  individ- 
uals lieh/iiging  to  it.  In  L.  iluc/i/lus  the  first  intcrradials  often  touch  the 
basals  only  at  the  anal  side,  while  in  L.  niclma,  they  rest  upon  the  ba.sals  at 
nil  live  sides.  Again,  in  the  fc-nur  species  there  is  generally  an  anal  plate 
between  the  intcrradials  of  the  second  row,  while  in  L.  mclma  that  plate  is 
scarcely  ever  represented.  Departures  of  this  kind  within  n  genus  in  respect 
to  characters  wliich  have  always  been  regarded  as  of  the  utmost  significance 
for  distinguishing  fi'n.ilies  and  genera  show  how  idle  it  is  to  expect  absolute 
accuracy  in  i!i.  separation  even  of  very  important  groups. 

Lyriocrinus  daotylus  Ww-i- 
Plate  XI.  Fiijii.  Su,  h,  c. 

',U^      m'<  r»,~   i,  ■■■!;■■:  il,irf,//iit  —  II.VI.I.;  (!(■(.].  Hep.  Uli  HiMr.  N    Y  ,  ]).  Ill 

.  ,:i2.    Zvf.  •/.,,.,/•  ,,W,-«.«—  Mali.;  ruliionl.  N.  V.,  Vi.l.  II.,  p.  W.  imi.!  tl,  Figs.  hi-y. 

1881.     LyriorfiHtjii  Jaclylu*  —  W.  "i"!  Si-.;  Ucvisimi  raliiMipi-.,  I'lirl  11.,  ;>.  iO.'i. 

Calyx;  semi-globose:  basal  regions  llatteiied,  tlie  centre  abruptly  dc- 
pres.sed  for  the  reception  of  the  column.  Surface  of  plates  smooth  or  finely 
corrugated.  Infrabasals  very  small,  restricted  to  the  bottom  of  the  colum- 
nar concavity.  T.asals  large,  four  of  them  angular  above,  that  of  the  anal 
side  truncate.  Uadials  wider  than  high,  larger  than  the  costals,  slightly 
touching  each  other  laterally  except  on  the  anal  side.  Arms  ten,  simple; 
heavy  at  their  bases,  tapering  upwards  to  one  half  their  former  size.  They 
are  composed  from  the  calyx  up  of  two  series  of  alternate  plates  with  parallel 
transverse  faces,  and  have  a  shidiow  groove  along  the  median  line  ;  then'  two 
])roxiinal  plates  incorporated  into  the  calyx.  Interlnaehials :  1. '.',  I  ;  those 
of  the  first  and  second  rov  .  large ;  the  lower  one  almost  touching  the  basals ; 
the  upper  one  smaller  und  somewhat  inllected  at  the  upper  end,  resting 
between  the  lower  nr.a  plates.  Another  ;-n  all  pli'e  is  placed  between  the 
distichals  so  that  the  arms  are  separated  ar.  oiie  side  by  an  interbrachial,  and 


RHODOC'RINID.K. 


2G3 


at  the  other  by  nn  interdiHtifhnl.  The  first  pliito  of  the  nnnl  side,  wliich 
toiiclies  the  biisals,  is  hirger,  and  is  geiieniily  followed  by  three  plates  in  the 
second  row.  Coluiiin  round ;  composed  near  the  calyx  of  nioderattly  high, 
thicker,  and  thinner  joints. 

J/iirixoH  awl  Loidlili/.  —  Niagara  group ;  Loekport,  N  Y. 

Ti/iwn  in  the  American  Museum  of  Natural  History  at  New  York. 


m   ' 


Lyriocrinus  melissa  (IImi.). 
r/u/c  XI.  Flux.  4,1,  !>,  c,  (/,  <■./. 

1803.     RlinilorriHHt  rnelium  —  IIai.i.;  Trims.  Allmiiy  lii'.t  ,  |i.  MIS  (Abslr.,  |>.  -J). 

1870.     RliiiilturiiiMn  (l,iriiii-ii)iii«)  iur/i<xii —  llAi.r.;  iH{h  lti|i.  N.  V.  Slalc  Mils.  Xal.  Ilisl.  (Mus.  edit),  ]>. 

i:t'.»,  I'lulr  1,-.,  Fiirs.  ls.>7. 
1881.     LyriijiviiiHi  m,li»ii  —  \V.  mill  Si'   ;  Ucvisinii  I'liltcoor.  I'liil  II.,  p.  •H)j. 

Calyx  dopres.sed,  nearly  twice  as  wide  as  high,  distinctly  flattened  to  the 
top  of  the  radials,  then  curving  rapidly  upwards  initil  llie  ^ides  of  the  upper 
part  are  at  right  angles  to  the  truncated  lower  part.  Ilasal  portions  foiining 
a  deep  pit,  which  is  surrounded  by  a  pentangular  rim,  interradially  arranged, 
and  having  a  triangidar  node  at  each  angle.  Surface  of  plates  flat,  Hmootii 
or  finely  corrugated. 

Infrabdsals  very  small.  eoiipeide(l  by  the  column.  Rasals  elongate,  gener- 
ally truncated  at  the  upper  face,  the  lower  hall'of  the  plates  eurve(l  inward, 
forming  the  sides  of  the  concavity,  the  upper  iialf  hori/ontal.  Hadials  large, 
wilier  than  high.  Both  costals  hexagonal,  the  a.xillary  one  snuiUer.  its  tipper 
angle  truncated,  supporting  a  small  interdistichal ;  the  sloping  faces  support 
2x2  large  distichals,  which  are  followed  by  free  arm  plates  of  the  .sune 
order.  Arms  ten.  equidistant ;  tliey  are  stout,  long,  tapering,  aud  ('(uui^osotl 
of  sliort  pentagoi\al  pieces  ;  tlieir  pinnules  long  and  closely  arranged.  luter- 
brachials:  1.  2,  1.  1;  the  first  as  large  or  larger  than  the  raflials.  resting 
against  the  truncate  upper  fiices  of  the  ba.sals.  Anal  side  generally  not  (li.x- 
tinct ;  but  it  has  excoptionnlly  a  small  additional  jdafe  in  the  second  row. 
Ventral  disk  almost  flat,  barely  rising  aliove  the  dorsal  cup.  Interambu- 
lacral  spaces  .slightly  depres.sed  ;  orals  well  developed,  twice  as  large  as  any 
of  the  other  disk  plates,  and  more  convex.  Anus  sulK'entnd.  very  wide,  and 
apparently  connected  with  a  tube.  Column  uniformly  cylindrical,  the  edges 
of  the  nodal  joints  marked  by  a  continuous  row  of  small  noiles. 

ILiyhnn  mul  L<ir(t1ll>/.  —  Niagara  group;  Waldron  and  Ilartsville.  Ind. 

T'lpr-'f  in  the  American  Museum  of  Natural  History,  New  York. 


;   ! 


I 


raa^^^^^^^^amr^ 


lii 


MKLOCiaNID.K  (RoKMKit)   1855. 

Monocyclic.  Lowkii  iiu.uiiialh,  with  wkll  dki-inkd  iNTKiaiUACiiiALs  hetween  them, 

KOIIMINU    A    i:\UT   or  Tin;   UOltSAL   cur.       RaUIALS   in    contact   all   AIIOUNI). 

Aiutlt/nit  of  the  Qetura. 
I. 

TlIK    MVMMKTIIV    OK    TIIK     DOHSAL    Cl'l'    DlSTl'KIIKD     MY    ONK    OK     MOHK 

ANAL    ri.ATKS MkLOCKINITE.H. 

A.    1!a.sai..h  KivKj  ctPsrAi.s  nvo. 
a,   Fir»t  eiialiil  hexnijimul, 

Aniisuinscriiil  ;  intcrbradiials  and  intprilistichals  numor- 
oiis.     Vfiitral  disk  comiiosuil  of  very  small,  iru'gulur 

]il!itos.     Hasiils  siiiull Ohjptoerlnus, 

Arms  Msorial,  basals  vuiy  largi',  otlicrwisu  ri'si'iuMiiig 

(flyptm'rhtiia I'eriijIyplorriniiK. 

h.    F'trnt  costal  ijuatlrainjiilai: 

Arms  uiii.serial ;  iiiterbrachials  fowj   ventral  disk  com- 
posed of  largo  plates StellJiacriitus. 

U.     Hasals  kouk;   costalm  two, 
a.    Fimt  costal  licxwjonal. 

Arms  uniserlal,  arranged  in  gronps  j  simple  or  bifurcat- 
ing, distieliiils  two  to  fo\ir,  calyx  of  moderatii  si/.n  .  .  Mariacrlnus. 
Arms  long,  braiicliing  often  ;  palmars  and  arm  joints 
very  short,  deeply  interlocking.  iJisticlials  live  and 
upwards.  Calyx  very  large;  lower  palmars  partly  in- 
cluded in  dorsal  cup,  interbraehials  very  numerous  ,  Scypltocrlnus. 
The  rays  extended  into  live  tubular  trunks,  from  which 
biserial  arms  are  given  off  frouj  the  outer  sides  all  the 

way  to  their  tips ileloerinus. 

<'.    Hasals  tiikek  ;  costals  two. 

Arms  biserial,  simple  from  their  origin;  interbraehials 

few,  an  anal  plate  interposed  within  the  first  range      .    Macrostylocriniis, 

IT. 

Symmetry  of  douhal  rrr  rxDisTUKiiEi)  iiv  anal  J'LAtes  ....     Dolatockixitm. 
A.    Basals  koi-r;  costals  two. 
a.    Afm.i  hitrrinl. 

Arms  siniiile ;  arranged  equilatorally  around  the  calyx  ; 

base  obconieal Technocrlnus. 

Arms  dichotomous  ;   basal  eup  inverted;   interbraehials 

largo Corymbocriiins, 

H.    Hasai.s  thkkk,  small;  costals  two,  the  must  wi  adranoclak. 
«.    Anns  s!>iij)/e. 


I? 


llr 


I'l 


MKI.OCIMN'IIK'E. 


260 


Arms  liinnriiil.    Dorsal  cup  giilttiirliiiiato I'lttelliucrlnui, 

AriiiH  iiiiisi-riiil ;  dorHiil  i'ii|)  <li'|iruH8e(l ;  intcrhruvhiiila 
tew,  liiii^iliiiliiially  urniiiK'*')) 

C.       nAHAt.M    I.UIliK,    |-|lllll,\lll,V     TIIKKK,    AM  IIVMINKIt. 

a.  Con/lilt  two,  the  Jir»l  ijiiiiilruiii/iiliir. 

Iitlevbtiichialt  few. 

Dorsal  cup  HulH'yliiiilrical ;  liaHals  aiul  radials  very  large, 
ilisticliali)  Hiiiall ;  ariii.s  unknown 

Calyx  ilc|>ri-H.s)>(l-NuliKlol)o.si';  liasaln  Hniall,  inti'iliracliials 
fuw,  the  tirHt  t'xtrt'Mifly  huh'i-  Arms  liiscrial  niul  gen- 
erally hranchint;.  Slit-like  respiratory  i)oros  at  tho 
sides  of  the  aniliidaeral  openin^js 

b,  Co»fnh  mil' ;  jinitinii/iiltir. 

Otherwise  resenililintj  yMA/i'<(()i«».t 

iaturhrachials  numerous,  hasals  forming  an  inverted  cup 

Genliitfiral  iiuil   tlini/nijifiiriit  l)iiitribution. 

Number  of  known  apeotes. 

(0|icu  flf(ures  iiidicato  Aincricaii ;   llinsc  marked  (  ),  Europenii  ) 


Altucrinut, 


Centrocrinu*, 


I>ul<ttii'-rinu», 

Slenofriniin. 
IJadrucrtnim, 


1 
i 

> 

i. 
;-) 

1 
■7. 

»' 

FuRHATIOH. 

HlLOCUHIIIJIf 

Aiiiaricnii. 

Ill 
111 

.Mi'IiH'riiiites. 

DiiliiiiKriiiitcH. 

3 

a 
C 
5 

5 

i 

i  \ 

a 

•c 

i 

"ti 

x 

a 

i 

C 

•5 

1 

(.1) 

I 

(3) 

1 
3 

s 

(U 

a 
"H. 

5' 

i 

c 

'x 
3(9) 

i 

a 
X 

? 

E 

6 
0 

i 
1 

k 
S 

a 

i 

i 

e 

1 

(7) 

a 
•c 

T 

2 
3 

a 

B 

•c 

£ 

1 

i 

a 
'C 

1 

e, 

8 
S 

* 

3 

1 

J 

1 

Ilnniiltiiii. 

I'p.  Ili'Morlierg. 

rp.  l>evon. 

2 
2 

2 
2 

Eifel. 

— 

I(T) 

i 
2(3) 

( triiiknny. 

2 
3 

(«) 

(6) 

Ix>w.  Ilplclcrlierg. 

Grail  wncke. 

Nia);nm. 

\V.Mil.H;k. 
Itolieinia. 
(iutlnud. 

4 
3 

7 

(1) 
(1) 

5(4) 
II 

(a.-i) 

lluiUun  Kivcr. 
Trenton. 

1 

1 

,3 

T(it!(l  »|yciei  95  |  JJ. 

r^ 


•  Expliiiliiip;  P./utminatusviwi  P.  duplicatHS,  wliicli  probably  belong  to  Slariaerixui,  aud  P.  ehia$lodiie- 
/fills  and  i*.  jii/iiiiiMut,  wkicU  are  young  spccimeus. 

34 


U...S!""!i^ 


2(]G 


Tin:  (UINOIKKA   (  AMKUATA   OF   NOUTII    AMKUK  A, 


luiiiin/i.t.  —  The'  Milocriiiidii-  itiul  KiK'uIyptiMTiiiiilu'  mo  llie  oi\\y  mono- 
cyclic  faiiiilif.'^  uf  tlu>  Caiin'iutu  wliicli  liiivo  ii  pontiigoiial  Iiuko,  uiul  in  whicli 
tlio  riidialM  aiu  in  cuntaet  nil  aiuund.  Tliu  laltor,  howuvur,  lU'piut  from  the 
Mi'iociiniilu!  so  wiiU-ly  in  their  ventral  Hlnietiiro  that  tiu-ri'  in  no  need  of 
further  ^•onlpllri^^on.  The  Melocriiiidji'  in  many  rcHpectM  nlno  weem  di(xi'ly 
related  to  the  Ai-tiiiociiMiila',  whieh  I'olluwed  them    in    time.      Indeed   the 


CrJC-o 


Flo.  li    MilurriHHn.  Fr(i.  IM.  S/ertnfriniii. 

(Fur  ilic  cxplniiatinn  of  the  leltcM,  »ec  Fig.  II.) 

Huperficial  ro.«*emhlance  hetween  the  two  families  is  often  quite  ninrkod,  Imt 
a  Mulucrinoid  is  always  readily  distinguished  from  an  Actinocriiioid  by  the 
al)senre  of  an  anal  plate  Itetween  the  nidiiils,  and  the  consequent  form  of  its 
Ijnse,  which  is  peuliigonal.  The  Melocriuidie  are  among  the  earliest  known 
forms  of  the  Camerata,  being  already  found  to  the  extent  of  six  species  in 
the  Trenton  group,  contemporaneously  with  the  earliest  Hhodocrinidie  nnil 
Reteocriiiidii'.  They  increased  in  ninnlicr  in  the  Upper  Silurian,  but  becanu' 
extinct  beforr  the  close  of  tlin  D'nonian.  before  the  appearance  of  the  Actino- 
crinidiv,  so  lar  as  existing  collet  ('ons  show.  The  family  includes  fifteen  gen- 
era, of  which  ninety-five  species  are  known  ;  fifty-four  from  America,  and 
forty-one  from  Europe. 

Some  of  the  gcnorn  referred  to  this  family  have  n  perfectly  pentamerous 
dorsal  cup,  the  posterior  intorradius  being  identical  with  the  other  four;  but 
in  others  there  are  one  or  more  anal  plates  interposed  between  the  inter- 
brachiaN,  by  winch  the  pentdmerou-s  symmetry  i"  disturbed.  If  this  difTer- 
cnce  were  well  marked  and  cdnstant.  it  would  affor  1  a  basis  for  separation, 
founded  on  the  more  or  less  complete  ab.senoe  of  anal  s.'ructiires  from  the 
dorsal  cup;  but  this  being  not  the  case,  we  arranged  the  genera  only  into 


MKLO(  UINID.K. 


2C( 


Miil)iliviMiuiiM  witli  rororcnoc  to  it.  railing  tliosc  in  which  Noiitf  triicu  of  mini 
pIntuM  i.s  roiiiiil  Mcidcrinitt's,  mitl  tlmsi!  in  wiiicii  llivy  aru  «'oni|>lt>t('lyal)'-i'nt 
in  llio  cup  DolalocriuitoH.  Wu  liml  it  inipo-'^iblu  to  niai<(!  tiif<i>  (livi>ionM 
fainilieH,  becanxo  they  noi'in  very  intiuiuti-ly  ri'latf<l  in  othi-r  ifspfctH,  and 
nhadc  into  oacli  otlior  (oo  I'lo.sfiy,  —  hiith  lonnH  l»t'ing  poxniliiy  n-prt'sonti'il 
ii'  -pccicH  of  tlu!  caiiu!  };t'nii!<.  Thin  1^  prolialily  tiiv  cnMu  in  J/iiilnnrliiii.t ; 
whili'  in  Alliiciiiiii.i  tiiu  liiNt  inlt'iltracliial  ol°  tlic  poHtfrior  nidu  is  "iiniuwliat 
larger  than  thu  (Mjrn'-pondin;^'  plate  ol'  the  other  sidcM. 

Thu  nainu  Mclocrinidio  wuh  intruducud  by  llovinur.*  it  was  applied  hy 
him,  and  afterwards  hy  Anm'lin.t  ZittLd.:];  and  S.  A.  Miik'r.^  oxdiisively  to 
;^onoru  with  loin'  hasals,  or  tiioso  that  were  supposed  to  havo  four.  Ith/iilif 
i-rliiiiK,  with  live  liasal"',  although  closely  allied  to  MiirinrrltiU!<  and  Milnciiiiiin, 
was  referred  l>y  /iltel,  and  S.  A.  Miller,  who  subslautially  adople<l  Zitttd's 
classification,  lo  the  (ilyptocriiiiihi^  under  wliicli  thoy  incliidud  a  variety  of 
genera,  both  monocyclic  and  dicyclic.  In  the  classification  of  IH'.MI,  Miller |{ 
refers  to  the  fllyplocr'  ho  Ciijiii/'ifi'liiiis,  (ih/jitnrrliiiis,  J'/frimrrliiiis,  Silihit- 
rn'iiiis,  and    Slji/iniun  —the  (irst  an   I(dilhyocrinoid  ;    S!jtliiiii<iir!iiiis  —  a 

Thysanocrinoid  —  ami  both  of  these  last  dicyclic.  This  is  the  more  curious 
because  Miller  is  the  author  of  Siplmiiurrinux,  which  he  described  as  having 
three  infrabasals ;  while  he  emphatically  denied  the  presence  of  infiabasals 
in  (!li/pt(ii'riniix  ;  and  yet  in  establishing  the  families  of  the  Criimidea 
made  the  "  presence  oi-  absence  of  •  subrailials'"  next  in  importance  "  to  the 
number  of  basals,"  upon  whi(di  his  classification  is  principally  based. 


i 


Ii     ^ 


!• 


I.   MKLOCIilNITES. 

SYM.MKTnY   OK   TIIK    DORSAL   Cri'    HHTIIIllKIl    ItV   ONK   Oil    MOllK    ANAL   PLATE-S. 


0LYPT0CRINU8  Ham,. 

1817.  1Iai,i.;  riilirmit.  \,w  Yciik,  Vol.  I.,  p.  iso. 

IS.'il.  Mrrnv;  Sviiii|i».  Urit.  i'lilii'oz    Kiiss.,  p.  .1(1 

I'l.'ill.  Hii.l.l.viiH;  Ciiiiiiil   Niiliinill^t  iiikI  (ic'dliiKist,  Nn.  1.,  p.  40. 

18,-)7.  Hn.I,IN<i»;  (iri>l.  Siirv.  <';iim.lii  iif  IS:.;)  In  IS.IO,  p.  850. 

1S50.  Hll.MNOS;  iliid.,  Dermic  IV,  p   .1.'). 

lH7;t.  Mkk.k  ;  (icdi.  Siiiv.  OIlio,  I'liliiMMil  ,  V.il   I.,  p.  30. 

1S7I.  S.  A.  Mii.i  Kli ;  firiciii.  Quurt.  .loiini,  Sci  .  p  .IIS. 

1S79.  ZiTTKi.;  llriiiilli.  ilcr  rnliuiihl  ,  Vol.  I.,  p  375. 

•  I,ctliini  ficos-ti.,  IS.I.-i  (AiiiK.  3),  p.  82S. 

f  Iciiimur  C'riii.  Siipoiii'.  p   10. 

X  Hiiiiill).  ,l,r  I'.ilir.iiilnloitii-,  Viil.  T.,  pp.  3nS-37.'>. 

\  Amor   I'liliiriz.  Fnssils  (scrmiil  cilil  ),  p.  270. 

II  Ainrripaii  Geolojjist,  Vul.  IV.,  pp.  275  to  280,  mid  pp.  310  to  357. 


^^J^ 

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268 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


1S81. 
1883. 
1883. 

1885. 
1859. 


W.  nnd  Sp.  ;  Revision  PaliEocr.,  Part  II.,  p.  185  (Proceed.  Acad.  Nat.  Sci.  Pbila.,  p.  359). 

W.  and  Sp.  ;  Aincr.  Journ.  Sci.,  Vol.  XXV.,  pp.  255  to  868. 

S.  A.  MiLLEu;  Aiiier.  Journ.  Sci.,  7ol.  XXVI.,  pp.  105  to  113  ;  and  Cincin.  Soc.  Nat.  Hist.,  Voi., 

VI.,  pp.  220  to  228. 
W.  nnd  Sp.  ;  Revision  Palaeocr.,  Part  III.,  p.  102  (Proceed.  Acad.  Nat.  Sci.  Phila.,  p.  324). 
S.  A.  Mii.LKu;  North  Anier.  Geol.  and  Paloiont.,  p.  H7. 

Not  Glyptoerinm  D'Oubig.ny,  1852 ;  Cours  Element,  de  Pal^ort.,  Vol.  II.,  p.  142,  nor  Prodr6me, 
Vol.  I.,  p.  47. 

Not  Qlgptocrhm  IIai.i,  1803,  Trans.  Albany  Inst.,  Vol.  IV.,  p.  202 ;  nor  28tli  Rep.  N.  Y.  State 
Mus.,  p.  Vii:=:Manarri>iui. 

Not  Gtyptocrinm  Hall,  1872;  24tli  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  p.  206  =  Seteocrinus. 

Not  Glyptocnnm  IIall,  1872;  ibid.,  p.  iOT :=  Pti/cho<riiiui. 

Not  Glyplocrinm  Wetherbt  ;  Journ.  Cincin.  Soc.  Nat.  Hist.,  Vol.  IV.,  p.  83  =  Reteocrinut. 

Not  Oli/ptocriniis  S.  A.  Miller;  ibid..  Vol  IV.,  p.  74  =  Compsoeriniis,  nor  p.  75  ^  Reteoerinus, 

Not  Glyplocrinus  Etiieridge  and  Nicholson,  18S0,  Siliir.  I'oss.  of  Girvan  Distr.,  p.  328. 
Syn.  Fosnil  Enrriiii/e  AmiiOTUt,  1838;  Anier.  Journ.  Sci.,  Vol.  XXXV.,  p.  405. 
Syn.  Icosidactylocrinitei  Owen,  1843  (Catalogue  name). 
Syn.  PycHOcrinus  8.  A.  Miller;  Journ.  Cincin.  Soc.  Nat.  Hist.,  Vol.  A'l.,  p.  231. 

Calyx  obconical  or  subglobose;  plates  thin,  often  highly  ornamented;  the 
fixed  brachials  pa.ssing  imperceptibly  into  arm  plates,  and  the  interbrachials 
into  disk  plates ;  the  arms  rising  vertically  from  the  edge  of  the  tegmen. 

Basals  five,  of  uniform  size,  forming  a  small  cup.  Badials  and  costals  of 
nearly  equal  size  ;  the  second  costil  hexagonal.  Distichals  varying  in  num- 
ber, there  being  but  two  in  species  in  which  palmars  take  part  in  the  calyx ; 
but  when  the  second  bifurcation  takes  place  in  the  free  arms,  they  are  quite 
numerous,  frequently  six  to  eight  or  more  in  the  calyx,  followed  by  several 
others  in  the  free  arms.  When  this  is  the  case,  the  second  distichal  gives 
off  a  large  pinnule ;  while  in  the  other  the  proximal  pinnule  is  developed 
into  an  arm.  Arms  rarely  branching  beyond  the  second  b'furcation,  rising 
vertically  from  the  calyx;  they  are  long,  slender,  roimded  on  the  back, 
and  composed  of  a  single  series  of  short,  slightly  wedge-shaped  pieces, 
which  do  not  interlock.  Pinnules  slender,  closely  arranged ;  the  proximal 
ones  the  stoutest,  and  frequently  incorporated  into  the  calyx. 

Interbrachials  definitely  arranged ;  the  first  large,  resting  upon  the  slop- 
ing upper  faces  of  the  radials ;  there  being  two  plates  in  the  second  row,  and 
two,  sometimes  three,  in  the  higher  ones.  The  anal  side  wide.st,  having 
generally  three  plates  in  the  second  and  all  succeeding  rows.  Interdistichal 
spaces  large,  composed  of  numerous  small  plates ;  some  species  also  have 
interpalmars.  Ventral  disk  depressed-hemispherical,  very  slightly  extend- 
ing above  the  level  of  the  arm  bases;  the  ambulacra  subtegminal,  except 
near  the  periphery,  where  some  of  the  small  covering  pieces  are  exposed, 
but  the  course  of  the  ambulacra  is  indicated  by  surface  ridges.  Flates 
of  the  di,sk  very  minute  and  irregularly  arranged,  decreasing  in  size  toward 


fr    I 


MELOCRINIDiE.  269 

the  arms.  The  arrangement  of  the  larger  plates  at  the  summit  is  also  irreg- 
ular, being  unlike  that  of  oi'als,  which  probably  are  not  rqjresented.  Anal 
opening  excentric,  at  the  summit  of  a  small  protuberance.  Column  round; 
axial  canal  large,  pentalobate,  die  lobes  directed  interradially,  except  in  one 
species  in  which  the  stem  is  pentangular  and  the  cential  canal  radialhy 
disposed. 

Distribution.  —  Glf/ptocrinus,  as  now  amended,  is  confined  to  the  Trenton 
and  Hudson  River  groups,  and  probiibly  is  restricted  to  America. 

Ti/pe  of  the  genus.  —  Oli/ptocnims  decadactyhis. 

Bemarks.  —  The  genus  agrees  in  the  uniserial  arms  and  its  general 
structure  with  Mariucrimis,  but  that  has  four  basals  instead  of  five.  It 
resembles  Compsocriutis,  whicli  has  also  four  basals,  but  an  anal  plate  in 
line  with  the  radials,  which  throws  it  into  the  Batocrinida). 

The  European  species  referred  to  Glyptocrinus,  with  the  possible  excep- 
tion of  G.  basilis,  belong  to  other  genera.  The  specimens  described  under 
the  name  Glyptociimis  ylubularis  by  Nicholson  and  Etheridge  probably  belong 
to  Archwocrinus.  They  evidently  had  infrabasals,  for  the  intcrradials  rest 
upon  the  basals,  ar.d  they  probably  had  biserial  arms. 

The  following  species  either  are  synonyms,  undeterminable,  or  are 
removed  from  Gli/ptocriims  to  other  genera: 

Glyptocrinus  parvus  Hall,  Teterted  to Ptychocrinus. 

"  any!(/rt>*is  Miller  and  DvEB,  synonym  of   ....  IHychocrinus  parvus. 

"  j/mciVis  Wktherbv,  synonym  of Ptychocrinus  pamts. 

"  Harrisi  Miller,  referred  to Compsocrinus. 

"  Carleyi  Hall,  "  Mariacrinus. 

"  miamiensis  SIiller,     "  Compsocrhms. 

"  Baeri  Meek,  "  Xenocrinus. 

"  expansus  Phillips,       "  Sagenocrimts. 

•'  armosus  McCiiesney,  "  Siphonocrinus. 

"  siphonatus  Hall,  synonym  of Siphonocrinus  annosiis. 

"  nobilis  Hall,  referred  to Siphonocrinus. 

"  eoqnatus  Miller,  synomym  of Reteocrinus  Onealli. 

"  O'NealU  (Nealli)  Hall,  "  Reteon-inus. 

"  lacunosus  lUhhinGS,         "  Archceocrintts. 

"  subnodosus  Walcott,       "            ........  Rhaphanocritius. 

"  sculptus  Miller,  "  Rhaphanocrinus. 

"  argutits  Walcott,  "  Stelidiocrinus. 

"  priscns  Billings,             "           ........  Periglyptocrinus. 

"  fimbriatits  Shumard,  undeterminable. 

"  libanus  Safford,  not  defined. 

"  plumosus  Hall,  detached  column  and  arms. 

"  quinqueparlitus  Billings,  detached  column  and  arms. 

"  Pattersoni  Miller,  undeterminable. 


i.' 


I 


'/ 


n-.-i  - 

III:!'  ■ 


iHi: 


W 


m 


Hir 


270 


THE   CRINOIDEA   CAMERATA   OF   KOUTII   AMERICA. 


I 


Olyptocrinus  deoadaotylus  iiali,. 
PMe  XX.  Figs.  4a-e  and  Plule  XXI.  Fiijs.  4a,  b. 

1G47.  Hali,;  I'ahconl.  X.  Y.,  Vol.  I.,  p.  2S1,  Piute  77,  FiRa.  l«-/'iiml  I'late  78,  Figs.  l«-«. 

1873.  MiiEK;'Pala'()iit,  Oliio,  Vol.  I.,  p.  30,  Plate  2,  Figs.  U,  b. 

1879.  Ziftel ;  llaiiilb.  d.  Palieont.,  Vol.  I.,  p.  375,  Fig.  202. 

1881.  W.  and  Sp. ;  Kevisioii  Pateocr.,  Part  II.,  p.  ISS  (Proceed.  Acad.  Nat.  Sci.  Pliila.,  p.  362). 

1883.  S.  A.  Miller;  Jouru.  Ciiiciii.  Soc.  Nat.  Hist.,  Vol.  VI.,  )).  220,  Plate  11,  Fig.  1. 

Calyx  obconical,  somewhat  higher  than  wide ;  the  interratlial  and  iiiter- 
distichal  .spaces  a  little  flattened,  giving  a  cross-section  pentagonal  through 
the  costals  and  decagonal  through  the  distichals.  Surface  beautifully  orna- 
mented with  radiating  angular  ridges ;  those  following  the  rays  to  tlie  arms 
a  little  the  largest  and  most  prominent.  Other  ridges  pass  sideways  from 
tlie  centre  of  the  plates,  meeting  with  similar  ridges  from  the  interbrachials, 
which  divide  the  surface  into  numerous  triangular  impressed  areas. 

Basals  small,  their  width  at  the  top  greater  than  the  height.  Eadials 
heptagonal,  larger  than  the  basals,  and  as  wide  as  long.  First  costals  a  little 
smaller  than  the  radials,  and  hexagonal ;  the  .second  as  large  as  the  fir.'<t,  but 
angular  above.  Distichals  two,  comparatively  large.  Arms  twenty,  simple, 
rather  stout,  cylindrical.  The  four  lower  plates,  which  in  large  ^'peciInens 
are  incorporated  into  the  calyx,  are  elongate,  but  decrease  in  length  upward  ; 
their  upper  and  lower  faces  being  parallel,  the  succeeding  free  plates  .slightly 
cuneate.  Pinnules  long,  closely  arranged  ;  the  proximal  ones  given  off  from 
the  third  palmars,  there  being  none  from  the  distichals.  Interbrachials 
numerous,  gradually  decreasing  in  size;  arranged  in  ten  to  twelve  ranges: 
1,  2,  2,  2,  dc,  at  the  regular  sides,  sometimes  with  three  plates  in  the  second 
row.  Anal  side  having  three  plates  in  the  second  and  succeeding  rows;  the 
l)lates  of  the  median  series  longitudinally  arranged,  and  covered  by  a  ver- 
tical ridge  similar  to  the  ridges  along  the  rays.  Interdistichals  in  four  to  five 
rows,  the  interpalmars  in  three  ;  the  former  arranged  :  1,  2,  2,  2,  2 ;  the 
latter  placed  in  a  single  longitudintvl  row.  Ventral  disk  slightly  convex, 
composed  of  irregular  pieces  with  a  small  prominence  in  the  centre.  The 
plates  are  smtill,  and  gradually  decrease  in  size  outward,  those  along  the 
margin  being  quite  minute,  and  enclose  some  of  the  "  SuumiMiltchcn."  The 
latter,  which  are  also  frequently  preserved  upon  the  arms  and  pinnules,  con- 
sist of  two  very  small  irregular  rows  of  pieces.  Anus  subccntral,  at  the 
iqiper  end  of  a  protuberance.  Column  round,  of  moderate  size,  the  nodal 
joints  a  little  the  widest ;  axial  canal  rather  large  and  pentalobate. 


.:7 


^- 


.; 


MELOCRINID.i:. 


271 


Ilumon  and  Locality.  —  Hudson  River  yroiip ;  Cincinnati,  0. ;  Wayncs- 
ville,  0.,  and  MayHville,  Ky. 

Itcmurks.  —  It  lias  been  supposed  by  several  writers  that  G.  (Iccaduch/hix 
had  rudimentary  infrabasals,  but  this  is  not  the  case.  In  a  fine  specimen 
from  which  every  vestige  of  the  stem  was  removed,  we  could  follow  the 
interbusal  sutures  to  the  axial  canal,  and  found  the  latte;  to  be  interradial 
and  not  radial,  the  part  which  had  been  supposed  to  represent  tlie  infra- 
basals being  the  upper  stem  joint. 

Qlyptoorinus  Dyeri  Meek. 
Plate  XX.  Figs,  la,  h,  c ;  ami  Plate  XXI.  Fi'ffs.  3a,  b,  c,  and  Fig.  6. 

1872.  Meek  ;  Proceed.  Acnd.  Nat.  Sci.  Pliila  ,  p.  3U. 

1873.  Mekk;  Geol.  Rep.  Ohio,  I'alicont.,  Vol.  I.,  p.  32,  Plate  2,  Figs.  2rt,  i  (not  2c)- 
1881.     W.  and  Sp.  ;  Revision  Palieocr. ;  Part  II.,  p.  188. 

1883.     S.  A.  Miller;  Jonrn.  Oincln.  Soc.  Nat.  Hist.,  p.  222. 

Sjn.  G/^plocriiiiin  l)j/eri  vur.  sithylohomis  —  Meek;  1872,  Proceed.  Acad.  Nat.  Sci.  Pliila.,  p.  310; 

also  Geol.  Rep.  Ohio,  Pala'ont.,  Vol.  I.,  p.  34,  Plate  2,  Fig.  ic. 
Syn.  Glj/ptocrinm  subglohonus  —  W.  and  Sp. ;  1881,  Revision  Palwocr.,  Part  II.,  p.  189. 
Syn.  Glyptocrinm  Rkhardsoni  —  Wetiierii\  ;  18S0,  .Toiirn.  Cincin.  Soc.  Nat.  Hist.,  Vol.  II.,  p.  21.5, 

Plate  16,  Figs.  1  and  Iff. 
Syn.  Ri'leocriimn  Richardsoiii —  \V.  and  Sp.  ;  Revision  Palieocr.,  Part  II.,  p.  193. 

Of  the  type  of  Ghjptocrhws  decadactyhts,  but  the  Ciilyx  globose  instead  of 
obconical.  It  has  a  similar  ornamentation,  but  the  ridges  are  le.«s  angular, 
being  rounded,  and  those  following  the  radial  and  anal  plates  are  more 
prominent ;  the  arms  are  thinner,  and  the  second  bifurcation  takes  place  in 
the  arms. 

Basals  small,  much  wider  than  long,  with  a  sharp,  almost  circular  rim 
around  the  bottom,  which  extends  slightly  beyond  the  column.  Eadials  and 
costals  a  little  wider  than  long,  the  latter  somewhat  the  smallest.  Distichals 
nine  to  sixteen  or  more,  their  number  varying  among  the  rays,  the  five  to 
eight  lower  ones  forming  part  of  the  calyx,  the  others  being  arm  plates. 
The  two  lower  distichals  nearly  as  large  as  the  upper  co.'.tals.  The  succeed- 
ing plates  decrease  rapidly  in  size  upwards.  Their  second  plate  has  the 
form  of  an  axillary,  giving  off  to  the  outer  side  of  the  ray  a  large  pinnule ; 
the  third  is  quadrangular  and  bears  no  pinnule ;  the  fourth  plate  bears  the 
second  pinnule  at  the  inner  side  of  the  ray,  above  which  every  plate  is 
pinnule-bearing.  In  large  specimens,  as  much  as  six  pinnules  are  incorpo- 
rated into  the  calyx,  and  these  are  not  only  larger  than  the  succeeding  ones, 
but  are  placed  farther  apart.     The  apposed  fixces  of  the  distichals,  and  appar- 


■ 


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>  h 


i" 


Wi 


■■? 


r 

5 

s 

272 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


eiitly  of  all  arm  plates,  are  covered  with  well  marked  radiating  striae  and 
grooves.  The  arms  in  their  free  state  branch  but  once ;  they  are  rather  thin, 
especially  at  the  upper  ends,  and  composed  of  short,  somewhat  cuneate 
pieces.  Interradial  spaces  slightly  impressed  between  the  costals,  and  dis- 
tinctly  grooved  between  the  distichals.  First  interbrachials  about  as  large 
as  the  radials;  the  plates  of  the  second  row  a  little  smaller,  supporting 
a  fourth  plate  b  itween  their  upper  sloping  laces,  and  two  plates  in  the  next 
two  rows,  followed  by  numerous  small  pieces,  which  enclose  the  fixed  pin- 
nules. The  anal  area  is  a  little  wider,  having  three  plates  in  the  second  and 
all  succeeding  rows  up  to  the  first  pinnule;  the  middle  series  being  marked 
by  a  rather  conspicuous  ridge.  Interdistichal  spaces  elongate,  their  median 
portions  deeply  grooved ;  the  first  plate  large,  followed  by  two  plates  in  the 
second  row,  and  a  number  of  small  pieces  above.  Construction  of  the  ventral 
disk,  and  position  of  the  anus  unknown.  Column  round,  —  not  indistinctly 
pentangular  as  stated  by  Meek  ;  the  nodal  joints  somewhat  larger ;  the  axial 
canal  pentalobate,  and  moderately  large. 

Horizon  and  Locality.  —  Hudson  River  group  ;  at  Cincinnati,  Lebanon  and 
Waynesville,  Ohio,  and  also  found  at  Richmond,  Ind. 

I'l/pe  in  the  Museum  of  Comparative  Zoology,  Cambridge. 

Bcmurks.  —  This  species  is  readily  distinguished  from  G.  decachdyhs,  its 
nearest  ally,  by  the  uninterrupted  series  of  anal  plates.  It  is  quite  remark- 
able for  its  large  number  of  incorporated  pinnules,  of  which  the  proximal 
one.s  have  almost  the  proportions  of  armlets.  Meek's  G.  Di/eri,  var.  yloboms. 
which  we  thought  to  be  a  good  species,  judging  from  the  figures,  can  hardly 
rank  even  as  a  variety.  We  have  examined  the  type  in  the  Museum  of 
Comparative  Zoology,  and  find  it  to  have  all  the  characteristics  of  G.  Dyeri. 
Wetherby's  G.  Richardsoui  also,  which  we  once  regarded  as  a  lieteommw,  is 
based  upon  a  somewhat  aberrant  specimen  of  this  species. 

(?^  Olyptocrinus  Shafferi  Miller. 
Plate  XXI.  Figs.  3d,  e,f. 

1875.  GI)ptocr!nui  Sinferi  —  S.  A.  MiLimi;  Ciiicin.  QiinrtorljT  Journ.  Sci.,  Vol.  IT.,  p.  277;  and  18S0, 
Jouni.  Ciiicin.  Soc.  Nat.  Ilist.,  A'^ol.  III.,  p.  SSS,  Plate  7,  Figs.  2fl,  i,  and  3»,  4,  c. 

1881.     Glyptocrinus  Shafferi  — Vf.  and  Sp. ;  Revision  PnliEOcr.,  Tart  11.,  p.  189. 

1883.  Pj/cnocrinus  Shafferi— ?i.  A.  Miu.kk  ;  Joiirn.  Cincin.  Soc.  Nat.  Hist.,  Vol.  VI.,  p.  231,  and  North 
Amer.  Geol.  and  Palaiont.,  p.  276. 

There  is  but  little  doubt  that  the  small  specimens  which  S.  A.  Miller 
described  as  Ghjptocfinus  Shafferi,  and   G.  Shafferi,  var.  germanus,  and  for 


'I 

I 

r'li 


MELOCRIMD.i:. 


273 


which  he  afterwards  proposed  the  genus  Pf/ciiocrimm,  nro  young  examples  of 
Gl>/ptocrinus  Dtjiri  The  specimens  liave  vnriou.sly  from  nine  to  twelve  dis- 
tichals,  but  in  place  of  having  six  to  eight  of  them  incorporated  into  the' 
calyx,  only  one  or  two  are  calyx  plates,  the  others  being  free.  That  the 
specimens  are  comparatively  smaller,  the  column  stouter,  the  basals  propor- 
tionately larger,  the  interbrachials  and  interdistichals  less  numerous,  the 
arm  joints  higher,  the  pinnules  stronger  and  placed  farther  apart,  all  indicate 
a  less  mature  stage  of  individual  growth,  n  jihase  through  which  every 
Gljptoerinus  must  naturally  have  passed. 

Miller  defines  Pi/cnocrimis  as  follows :  "  Calyx  cup-shaped.  Column 
round.  Basals  five,  small,  pentagonal.  Trimary  radials  3x5.  Sec- 
ondary radials  none.  Regular  interradials  three.  Arms  ten,  but  some- 
times dividing  after  becoming  free.  Pinnules  dense  and  strong."  This 
description  would  apply  equally  well  to  any  young  Gli/ptocrimiK.  It  must  be 
remarked,  however,  that  both  of  Miller's  types  have  small  interdistichals, 
which  he  overlooked.  The  presence  of  these  plates  proves  conclusively  that 
at  least  one  of  the  distichals  takes  part  in  the  calyx,  and  that  "  secondary 
radials"  are  not  unrepresented  in  those  specimens,  as  Miller  supposed. 

Iforuon  and  LocalHy.  —  Found  associated  with  the  two  preceding  species 
at  Cincinnati  and  other  places. 

T//pe  in  the  collection  of  S.  A.  Miller. 


■ 


i'i 


P 


1 1 1 


li  '■■ 


■'\ 


OlyptOCrinuS  ramuIoSUS  Billings. 
Plate  XX.  Figs.  Ga,  h. 

1856.    E.  BliLiNGs;  Qniiadian  Naturalist  and  Geologist,  No.  1,  p.  54;  also  Geol.  Surv.  of  Canada  (Rep.  of 

Progress),  1857,  p,  258,  and  1859,  Decade  IV.,  p.  57,  Plate  7,  Fig.  2ff  and  Plate  8,  Fig.  1. 
1881.    W.  and  Si'. ;  Revision  Pnteocr.,  Part  II.,  p.  189. 
1883.     S.  A.  MiLLKii ;  Jouru.  Cinein.  Soc.,  Nat.  Hist.,  p.  221. 

A  large  species.  Dorsal  cup  obconical,  somewhat  rounded  at  the  base. 
Costals  and  distichals  remarkably  nniform  in  size ;  also  the  palmars  propor- 
tionally large.  Plates  almost  flat  and  without  any  markings,  except  a  con- 
spicuous, obtusely  angular  ridge  passing  up  the  rays,  occupying  nearly  one 
half  their  width. 

Basals  small,  only  the  upper  angles  visible  from  a  side  view.  Radials 
somewhat  larger  than  the  costals,  as  long  as  wide.  Distichals  six,  exception- 
ally seven ;  the  proximal  one  as  long  as  the  costals,  but  a  little  narrower; 
the  succeeding  ones  smaller.     There  are  fixed  pinnules  from  the  second, 

35 


I 


n'' 


frin 


07  • 


THE  C'lUNOIDKA  CAMKRATA  OF  NOIITII  AMERICA. 


foiutli  and  fifth  plates  (none  from  tlio  tliird),  which  arc  long,  but  not  ns 
conspicuous  ns  in  the  preceding  species,  and  they  grow  more  obscure  with 
age.  All  brachials  of  the  third  order  are  free ;  the  two  or  three  lower  ones 
are  longer  and  have  parallel  upper  and  lower  faces ;  the  others  being  short 
and  cuneiform.  The  arms,  which  branch  once,  are  long,  very  slender, 
rounded  on  the  back,  and  provided  with  rather  long  pinnules.  Interbrnchial 
plates  large,  to  the  fifth  row  nearly  of  equal  size,  and  as  large  as  the  second 
distichals ;  arranged  :  1,  2,  2,  2,  2.  From  the  sixth  row,  where  the  pinnules 
come  in  contact  with  the  intcrbrachials,  the  arrangement  is  less  regular,  and 
the  plates  gradually  grow  smaller.  There  seems  to  be  no  anal  ridge,  but  the 
posterior  interradius  has  three  plates  in  the  third  row,  and  frequently  in  the 
second.  The  interdistichal  spaces  are  remarkable  for  theii  great  length,  and 
the  large  size  of  the  plates ;  they  are  arranged :  1,  1,  2,  2,  3.  Construction 
of  ventral  disk,  and  position  of  anal  opening  unknown.  Column  round, 
cojnposed  of  short,  sharply  edged  joints. 

HiirizoH  ami  LncuVilij.  —  Trenton  limestone  ;  Ottawa,  Canada. 

Types  in  the  Canada  Survey  Museum, 

Olyptoorinus  ornatus  Billinos. 


Plate  XX.  Figs.  Ga,  h. 


1857- 


BiiiTNOs ;  Geol.  Surv.  of  Cnnndn  (Rep.  of  Progress),  p.  260  j  also  1859,  ibid.,  Decade  IV.,  p.  CO, 
Plate  9,  Figs.  2rt,  A. 
1881.    W.  mid  Sp.  ;  Kevisioii  Pnlxocr.,  Part  IT.,  p.  189. 
1883.    S.  A.  Miller;  Jourii.  Ciiioin.  Soc.  Nat.  Hist.,  Vol.  VI.,  p.  225. 

Of  the  type  of  Ghjptocrimis  Dyeri,  but  readily  distinguished  by  its  orna- 
mentation, the  smaller  number  of  interbrachial  and  anal  plates,  and  by 
having  ten  arms  instead  of  twenty.  Calyx  globo.se,  the  plates  delicate,  orna- 
mented with  five  or  six  rather  conspicuous,  finely  striated  ridges,  radiating 
from  the  centre  of  the  plates.  The  ridges  passing  up  the  radial  and  anal 
plates  are  more  prominent  and  broader  than  the  others ;  those  from  the 
intcrbrachials,  which  are  not  confluent  with  the  ridges  of  adjoining  plates, 
forming  a  well  defined  star  upon  each  plate. 

Base  short,  with  a  projecting  rim  and  a  shallow  depression  at  the  bottom. 
Radials  and  costals  a  little  wider  th.an  long,  the  radials  one  third  the  largest. 
Four  of  the  distichals  generally  take  part  in  the  calyx,  of  which  the  two 
proximal  ones  are  nearly  as  large  as  the  upper  costal,  the  second  pinnule- 
bearing  ;  the  two  succeeding  ones  are  much  smaller,  but  yet  twice  as  large 


MKLOCRIN'IO.i;. 


275 


as  the  free  bmcliiiiis.  Arms  ten,  Hlendor,  not  bifurciitinj^;  coini)0-e<l  of  qimd- 
nuigiilar,  luoilcrately  liiyh  joints  with  long  pinnules.  Interbrnehiiils;  1,  2,  2, 
2,  decreasing  in  size  upwards.  The  anal  interradins  consideiably  wider: 
1,  3,  3,  c/c. ;  the  middle  series  longitudinally  arranged,  and  marked  by  a 
conspicuous  ridge.  Interdisticlmls :  1,  2,  <./(;.  Construction  of  ventral  disk 
and  anus  uidcnown.  Column  obscurely  pentagonal  to  judge  from  the  top 
joint ;  the  axial  canal  of  medium  size.* 

Horizon  and  Lnml'iti).  —  Trenton  limestone;  Ottawa,  Canada.  -— — 

Types  in  the  Canada  Survey  Museum  at  Ottawa. 

Glyptoorinus  marginatus  Billin-gs. 
Plata  XX.  Fig.  2. 

1850.  Glyplorriiim  marginatus  — Y..  BiiiiNOs;  Gcol.  Siirv.  Caiimlii  (Ucp.  of  Progress),  p.  SCOj  also  1859, 

Dc'cndo  IV.,  p.  59,  Piute  9,  Fig.  \a. 

1851.  Atchroci-iiim  murginatm  —  VV.  and  Sp. ;  llcvisioii  Pulneocr.,  Part  II.,  p.  190. 
1859.    JrchtEocrinus  marginatus  —  S.  A.  Mar.Ea;  N.  Ainer.  Guol.  mul  Palitoiit.,  p.  225. 

A  large  and  well  marked  species.  E.vact  form  of  calyx  undeterminaltle 
—  the  only  specimen  being  in  a  crushed  condition  —  but  probably  subglo- 
bose.  Plates  evenly  margined  by  a  strong  elevated  border  crossing  the 
radial  ridges,  their  middle  portions  smooth  and  very  thin;  the  inner  floor  of 
the  plates  marked  by  slender  conspicuous  tubercles.  Radial  ridges  not  very 
prominent,  wide  and  flattened. 

Basals  small,  projecting  laterally.  Radials  and  costals  as  long  or  a  little 
longer  than  wide  ;  the  former  twice  as  large  as  the  costals.  Distichals  about 
seven ;  all,  or  nearly  all,  incorporated  into  the  calyx,  rapidly  decreasing  in 
size;  the  proximal  one  as  large  as  the  costals,  and  of  similar  form;  the  upper 
axillary,  and  succeeded  by  free  arm  plates.  Arms  delicate,  composed  near 
the  calyx  of  moderately  long  (nearly  as  long  as  wide),  slightly  cuneate 
joints.  There  are  apparently  no  fixed  pinnules ;  the  free  pinnules  long,  stout 
at  the  base,  distinct';,  '..pering.  Interbrachials:  1,  2,  2,  1,  2,  3,  2,  followed 
by  others ;  their  five  lo,  or  ones  of  nearly  the  same  size  as  the  radials.  Anal 
area  considerably  wider,  and  compo.sed  of  a  much  greater  number  of  plates 
than  in  any  other  species  of  the  genus.  It  contains  a  middle  series  of  anal 
plates,  marked  by  an  obscure  ridge,  and  to  both  sides  of  this  ridge  there  are 
numerous  interbrachials,  arranged  like  those  of  the  four  regular  sides,  but 

•  It  is  doubtful  if  the  detached  column,  which  Billings  found  associated  with  the  type  specimen,  belongs 
to  this  species. 


:    ^ 


27G 


TIIK  CUINOIDKA  CAMKRATA  OF  NOUTII  AMKKICA. 


tho  pliitt'H  Momcwliat  Hiiiullcr.  Notliiiig  in  known  of  the  ventnil  disk,  tlio 
aniil  opening,  ami  tlie  upper  portions  of  tho  arniM.  Column  Mtrony,  roinul  ; 
composed  oi'ultenuite  thick  mid  thin  joints,  all  rounded  along  tlio  edges,  the 
former  twice  as  high  na  the  latter,  and  somewhat  wider.  Arial  canal  large, 
pcntalohato. 

Il'irizon  ami  Lomlilj.  —  Trenton  liinostono  ;  City  of  Ottawa,  Canada. 

Itiinaihs,  —  Tliis  species  has  a  superficial  resemblance  to  certain  species 
of  Arc/neocriiiiia,  and  in  18S1  wc  referred  it  to  that  genus.  But  on  examin- 
ing tho  type  specimen  from  tho  Canada  Survey  Museum  we  find  it  has  no 
iufrabasals,  and  the  angles  of  the  axial  canal  are  interradially  disposed. 

(?)  Olyptocrinus  Fornshelli  s.  A.  Miller. 
Plate  XX.  Firf.  3,  and  Plate  XXI.  Fig.  5, 

1871.     S.  A.  Mlu.ER;  Ciiioiii.Qimrl.  Joum.  Soi.,  p.  348. 
1881.     W.  mid  Sp.  ;  lU-visiou  I'lila'ocr.,  I'nrt  II.,  p.  188. 

1883.     8.  A.  MiLLKii;  Jciuiii.  Ciuciii.  Sue.  Nut.  Hist.,  Vol.  VI.,  p.  227j  and  Nortli  Amcr.  Gcol.  and  Palte- 
oiit.,  p.  248. 

Calyx  elongate,  obconical ;  dorsal  cup  almost  twice  as  high  as  wide,  its 
sides  convex.  Plates  delicate  and  beautifully  ornamented,  being  traversed 
by  sets  of  from  five  to  seven  small  ridges,  a  set  directed  to  each  side  of 
the  plate,  and  each  set  continued  upon  adjoining  plates.  The  ridges  of  the 
same  set  are  parallel,  those  of  different  sets  meeting  at  an  angle  at  the 
middle  of  the  plates,  and  being  so  arranged  as  to  form  numerous  rhombs, 
each  containing  two  sets  of  included  triangles.  Upon  tho  radiols  and  costals 
tlie  median  ridge  is  but  slightly  stronger  than  the  others,  but  on  approach- 
ing the  distichals  it  enlarges  rapidly,  and  at  the  fifth  plate  it  attains  the 
proportions  of  an  arm. 

Basals  small,  forming  a  .short  cup;  the  interbasal  sutures  deeply  notched. 
Radials  and  costals  longer  than  wide,  their  upper  and  lower  faces  unusually 
narrow ;  the  first  costal  somewhat  longer  than  the  radials,  the  second  a  little 
smaller  generally.  Of  the  distichals,  the  ten  to  twelve  lower  plates  take 
part  in  the  calyx ;  the  three  proximal  ones  being  but  third  smaller  than 
the  costals;  the  fourth  is  considerably  shorter,  and  the  succeeding  ones 
almost  as  short  as  the  free  brachials.  Arms  bifurcating  (once  or  oftener), 
long,  very  slender  at  their  tips ;  constructed  of  moderately  short,  cuneate 
pieces  with  stout  and  long  pinnules.  Interradial  and  interdistichal  areas 
elongate,  and  composed  of  an  unusually  large  number  of  pieces ;  the  former 


I 


T 
1 


MKLOCUINID^E. 


277 


arrangcti  in  ono  uf  tlio  fpcciinouH:  1,  2,  3,  3,  3,  3,  3,  3,  i,  l ;  the  Iiittor: 
1,  2,  3,  3,  3,  etc.  Tlic  luiiil  side  contuinH  three  plates  in  the  necond  row,  and 
tliero  arc  otiier  extra  plates  above.  Nothing  is  known  of  the  veutrul  disk  or 
anal  opening.  Column  Hhar|dy  pentangular ;  the  nodal  joints  the  longCMt,  their 
ec1ge.s  (lattencd  (not  eonvex) ;  internodal  joints  short  and  angular  in  tho 
upper  part  of  the  stem,  but  gradually  growing  as  large  as  tho  nodal  ones ; 
axial  canal  wide  and  slightly  penfaloltate,  tho  lobes  disposed  radially,  in  tho 
same  direction  as  the  outer  angles  of  the  stem. 

Jloruon  and  Locali/i/. —  Upper  part  of  tho  Hudson  IJiver  group;  at  Mor- 
row and  Waynesvilie,  0. 

Ty/>es  in  tho  collection  of  Mr.  F.  L.  Fornslicll. 

ItetHiirks.  —  It  is  with  sonio  hesitation  that  we  place  this  species  iinder 
Gli/iitocnnm.  It  differs  from  all  other  species  of  the  genus  in  the  pentangular 
stem,  and  tho  radial  position  of  its  axial  canal,  a  feature  in  which  it  is  at 
variance  with  all  other  known  monocyclic  Palteocrinoids.  That  it  actually 
has  no  infral)asals,  we  ascertained  from  a  fragmentary  specimen  by  exposing 
the  inner  floor  of  the  basal  cup.  It  has  in  the  centre  a  large  pentangular 
open  space,  whose  angles  are  pointed  to  the  interbasal  sutures,  taking  the 
same  direction  as  the  angles  of  the  stem.  A  somewhat  similar  departure 
from  the  rule  is  clain)cd  to  exist  in  tlie  recent  genus  Pcntacrinns,  in  which, 
however,  stem  and  canal  are  Hito-radial. 


r 


!JI 


FBRIGLYFTOCRINUS  W.  and  Sp.  (nov.  gen.). 

Closely  allied  to  GJi/ptocrinus,  but  having  larger  basals  and  well  developed 
biserial  arms ;  the  arms  of  Gl>/ptocnnus  being  described  by  all  writers  as  uni- 
serial.  The  only  two  species  known  to  us  are  our  new  species  Perifffypto' 
crinus  BilUiigsi,  which  we  make  the  type  of  that  genus,  and  P.  jiriscus,  which 
was  described  by  E.  Billings  as  a  Gtyptoctimis,  Fragments  of  a  third  species 
are  found  in  Alexander  County,  Ills. 

Distrihiiioii.  —  Black  River  shale,  and  Trenton  limestone  of  Canada. 


'   1 


.^P    \^ 


(    : 

li    f 


! 


Feriglyptoorinus  Billingsi  w.  and  Sp.  (nov.  sp.). 

Plate  XXI.  Figs,  la,  b. 

A  beautiful  and  highly  ornamented  species.     Dorsal  cup  elongate-obcon- 
ical,  higher  than  wide,  somewhat  depressed  at  the  interradial  and  interdis- 


11. 


278 


THK  CULNUIDEA  CAMEUATA   OF  NOHTH   AMKItlCA. 


(ieliiil  "piicesi.  Tho  plates  niarkt'd  by  roundutl  liilgc-*,  ono  to  oacli  Ma  of  tlio 
pliitos;  tlioHU  iipuii  tliu  nuliiils  and  lixud  bnicliiul.<4  iiiiicli  wider  and  mure 
pruiiiineiit.  The  ridges  tapering  tu  the  inarginrt  ot'  the  [iliituH,  hu  an  tu  form 
bead-like  clevatiouH  along  the  rays,  nnd  a  well  defined  Htar  upon  each  Inter- 
brachiul. 

Dasids  largo,  forming  an  elongate  cup,  which  is  dreidy  grooved  at  the 
interl)asal  Miitures,  and  the  wideM  of  tho  jjlatcH  are  bordered  by  conspieuoii.s 
ridges,  which  aro  prolonged  to  tho  upper  part  of  the  radials.  lladials  and 
costals  largo,  longer  than  wide;  tho  radials  larger  than  the  costals.  Dis- 
tichals  two.  Pahnara  frco  from  tho  fourth  plate.  Arnis  twenty,  simple, 
long,  slender,  gradually  tapering  to  their  tips,  and  beyond  tho  fourth  or  fifth 
plate  strictly  bisorial.  The  first  pinnule  is  given  oil"  from  tho  second  pal- 
uiars,  and  all  succeeding  brachials  arc  pinnule-bearing.  Intorbrachials :  1,  2, 
2,  2,  2,  c/c;  the  lower  ono  considerably  tho  larger.  Interdistichals:  1,  1,  1  ; 
intorpalinars :  2  to  3.  Anal  interradius  tho  widest,  the  lower  plates  nome- 
Avhat  larger  than  the  corresponding  plate  of  the  four  other  sides.  It  con- 
tains three  idates  in  the  second  and  all  succeeding  rows,  tho  middle  s('rio.<» 
marked  by  n  somewhat  interrupted  longitudinal  ridge.  Similar  but  shorter 
ridges  proceed  from  tho  first  anal  pluto  to  adjacent  radials.  Construction  of 
ventral  disk,  and  position  of  anus  not  known.  Column  slightly  decreasing 
in  size  downward;  round;  composed  of  rather  long  joints  with  convex 
edges ;  the  nodal  joint.s  considerably  thickest.  At  three  inches  from  the 
calyx,  each  internode  contains  seven  to  eight  joints,  of  which  every  second 
or  third  is  nearly  as  largo  as  tho  nodal  ones. 

Iliir'izon  and  LncaVdy.  —  Trenton  limestone,  Ottawa,  Canada. 

7//y/c.s  in  the  Canada  Survey  Museum  at  Ottawa ;  collected  by  Mr.  John 
Stewart. 

We  take  pleasure  in  dedicating  this  elegant  species,  the  type  of  a  new 
genus,  to  our  friend  Mr.  Walter  R.  Billing-i,  the  author  of  several  important 
papers  on  Crinoids,  to  whom  we  are  indebted  for  many  favora. 


V 


Periglyptoorinus  piisous  (Bulixos). 
Pkde  XXL  Fig.  2. 


1856.     Oli/plocrimiii  prisem —  Y,.  BiLLrens;  Cool,  Surv.  Cnnndn  (Rep.  of  Progress),  p.  287;  also  1859,  De- 

ciule  IV.  p.  5(1,  I'late  7,  Figs.  \a,  h,  e. 
19S1.     Gli/plocriniis  prisnia  —  VV.  and  Sp. ;  Kovision  Pnlwocr.,  PnrI  IT.,  p,  189. 
1S83.     (!li/ploeriiiu» pmcm — S.  A.  Millkb;  Joiirii.  Ciiicin.  Soc.  Nat.  llisl.,  p.  225. 
1883.    (?)  Archteocrinm priscui  —  W.  aud  Sp.j  llcvision  Palieocr.,  Part  III.,  p.  301. 


' 


MKr.OCHINID.K. 


27tt 


■ 


A  Biiiall  upccicH.  Doi'Mal  cup  ohconiciil  with  uli^^'litly  convex  HidcM ; 
Ncction  iicrosM  tlio  co^tiils  Nliiirply  puiitii^oiial,  owing  to  tlie  t'on.H|)icnoiiM  radial 
rltlgoH,  which  paMH  from  Uio  urnm  down  to  tlio  cuntro  of  tliu  raUialn,  wluro 
they  divide  and  are  continued  to  the  l)aMalH.  The  ridgcH,  which  arc  rounded, 
grow  narrower  toward  the  middle  of  tiie  pliitcM,  widening  at  their  nuirgius, 
Surface,  e,\ce[)t  along  the  ridgen,  covered  with  nuineroun  Hnu\ll  pUHtuliM 
without  definite  arrangement. 

DasaU  large,  forming  a  pentagonal  cup  with  a  rim  around  the  bottom. 
Railialn  twice  or  nearly  three  tinicM  as  largo  oh  the  second  costals ;  the  t'lvnt 
costal  linger  than  the  Hoeo'id.  Dintichals  free  beyond  tiie  foifth  plato ;  the 
first  and  Hccond  couMiderahly  the  larger;  the  necond  one  pinnule-hearing, 
and  also  the  fourth  (not  the  third),  which  in  ulightly  wedge-Hhaped,  and  con- 
sidorably  smaller  than  the  preceding  ones;  from  the  fifth  to  the  eighth,  the 
platen  arc  decidedly  cuneato,  the  higher  ones  interlocking.  Arms  10,  simple 
throughout ;  thin,  composed  of  two  series  of  trigonal  pieces.  Interbrachials  : 
1,  2,  2,  civ.;  the  plates  large.  Anal  side  slightly  wider;  the  first  plato 
a  little  larger  than  the  corresponding  ones  of  the  other  sides ;  the  succeed- 
ing pieces  comparatively  smaller ;  there  are  three  plates  in  the  second  row, 
and  In  all  the  rows  above.  The  plates  of  the  median  series  are  formed  into 
II  conspicuous  longitudinal  ridge,  -i  'lich  divides  on  the  first  nnal  plate,  send- 
ing  a  branch  to  the  middle  of  adjacent  radials.  Nothing  is  known  of  tho 
structure  of  tho  ventral  disk  and  anal  oi)ening,  and  nothing  definitely  of  the 
column. 

Horizon  ami  LocalUt/.  —  Black  River  limestone ;  Renfrew  Co.,  Canada.    • — 

Tijpe  in  the  Canada  Survey  Museum  at  Ottawa. 

Remarks.  —  Tho  large  columns  which  E.  Billings  figures  from  the  Tren- 
ton  group  of  Ottawa,  and  which  he  thought  might  be  referable  to  O.  primm, 
probably  belong  to  a  different  species. 


STELIDIOCRINUS  An.ieli.v  (Restricted  by  W.  and  Sp.). 

1878.  AMOELtN;  Iconngr.  Crinoiil.  Siioc,  p,  21. 

1879.  ZiTTEL;  HiukII).  der  I'ulicoiit.,  Vol.  I,, p.  345. 

1881.    W.  mid  Sp.  ;  Ucvisimi  Piilreocr ,  Part  II.,  p.  98  (Proceed.  Acnd.  Nnt.  Sci.  Pliilii.,  p.  272). 
1885.    W.  mid  Sp.  ;  ibid.,  Part  III.,  p.  102  (Proeccd.  p.  324). 

Calyx  small,  subturbinate,  plates  smooth ;  interrndial  .ireas  depressed ; 
radial  plates  elevated  but  not  ridged;  ventral  disk  composed  of  but  few 
plates. 


|T!!V 


280 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


Basals  five,  forming  an  acute-angled  pentagon.  Radials  large,  wider 
than  long;  lunate.  Costals  two;  the  first  quadrangular;  the  second  much 
larger,  almost  as  large  as  the  radials.  Distichals  2  X  10  in  the  calyx,  the 
others  free  arm  plates.  Arms  ten,  simple,  uniserial,  rather  stout;  pinnules 
strong.  Interbrachials :  1,  2,  1 ;  the  first  very  large,  rising  to  the  top  of  the 
first  costals.  Anal  area  wider,  containing  three  plates  in  the  second  and 
third  rows,  and  smaller  ones  above.  Anus  excentric,  represented  by  a  simple 
opening,  which  faces  laterally.  Ventral  disk  low,  the  orals  very  large,  occu- 
pying in  *S'.  capitulum  fully  three  fourths  of  the  whole  surface.  Column 
round. 

Distribution.  —  Hitherto  found  only  in  the  Upper  Silurian  of  Gotland, 
Sweden,  but  we  now  refer  to  this  genus  Walcott's  Gli/ptocrinm  arguUts  from 
the  Trenton  limestone  of  New  York,  with  some  doubt. 

Remarks.  —  Angelin's  descriptions  and  figures  are  so  confusing  that  no 
uniform  generic  characters  can  be  deduced  therefrom,  unless  some  are  elimi- 
nated. Taking  the  first  species  S.  cajjUiilum,  Tconogr.  Plate  XVII.,  Figs. 
5-5(7,  ^^^^  ^h®  ^^^'^^  figures  of  his  second  species  S.  laevis,  ibid.,  Plate  XV., 
Fig.  20,  we  have  the  type  indicated  by  the  above  descriptions;  but  Plate 
XXVIII.,  Figs,  la,  1),  figured  also  as  S.  laevis,  is  clearly  a  DcsmiJocrinus,  and 
the  specimen  represented  on  Plate  XXXII.,  Figs.  3  and  3«,  is  probably  incor- 
rectly figured,  either  as  to  the  anal  side  or  the  arms.  Plate  XIX.,  Fig.  6, 
figured  as  S.  oralis,  is  a  totally  different  thing,  and  probably  belongs  to  the 
Rhodocrinidaj.  Plate  XXI.,  Figs.  G,  7,  described  by  Angelin  as  Ilarmocrinus, 
and  fonsidered  by  us  (Revision,  II.,  p.  99)  as  belonging  to  Stelidiocrimis,  has 
very  possibly  a  dicyclic  base,  and  strongly  resembles  Tlii/sanocrimis.  We  have 
not  the  material  to  settle  these  questions,  but  by  restricting  the  genus  to  the 
above  mentioned  forms,  we  have  something  tangible.  The  genus,  as  thus 
defined,  differs  widely  from  any  other  of  this  group,  especially  in  the  struc- 
ture of  the  disk,  which  is  quite  remarkable.  The  quadrangular  first  costal 
distinguishes  it  from  the  associated  genera  with  five  basals. 

(?)  Stelidiocrinus  argutus  (Walcott). 
Plate  XXIV.  Fig.  G. 

1883.     Oli/ptocrinut  argulus  —  Walcott  ;  35lh  Rep.  N.  Y.  Slate  JIus.  Nat.  Hist.,  Plate  17,  Fig.  9. 
1835.     0)  Stelidiocrinus  arpatiis  —  W.  and  Sp. ;  Revision  ralicocr.,  Part  II.,  p.  102. 

Calyx  small,  somewhat  pentangular;  the  interradial  spaces  depressed. 
Basals  five,  rather  large.     Radials  subquadrangular,  the  upper  faces  moder- 


' 


MELOCRIMDiE. 


281 


ately  concave ;  their  upper  corners  but  slightly  truncated.  First  costals 
quadrangular,  not  more  than  half  the  size  of  the  radials,  a  little  wider  than 
long,  the  lower  face  convex.  Second  costals  nearly  as  large  as  the  radials, 
their  upper  faces  forming  an  obtuse  angle.  Distichals  one  in  the  calyx. 
Arms  two  to  the  ray ;  composed  of  rather  stout  quadrangular  pieces.  The 
two  or  three  proximal  free  plates  about  as  long  as  wide,  the  others  compara- 
tively longer,  and  increasing  in  length  upward.  The  pinnules,  which  are  very 
stout,  almost  take  the  form  of  arndets;  they  are  placed  far  apart,  and  their 
joints,  like  those  of  the  arms,  grow  longer  upwards.  Interbrachials  three 
preserved  in  the  specimen,  but  having  others  above ;  the  arrangement  of  the 
plates  at  the  anal  side  unknown.  Column  of  medium  size;  the  joints 
rounded  at  their  edges,  and  decreasing  in  height  downward. 

Ilorkon  and  Locality.  —  Upper  part  of  Trenton  limestone;  Trenton 
Falls,  N.  Y. 

Tz/pe  in  the  Museum  of  Comparative  Zoology,  Cambridge. 

Remarks.  —  We  refer  this  species  with  some  doubt  to  StcUdiomnus,  which 
it  approaches  in  its  general  characters ;  but  as  nothing  is  known  of  the  struc- 
ture of  its  anal  side,  it  may  belong  to  a  different  genus,  and  perhaps  to 
the  Dolatocrinites. 


1  I 


MARIACRINUS  Hall  (emended  W.  and  Sp.). 

1859.  Hall  (in  part)  ;  Palicont.  N.  Y.,  Vol,  TIL,  p.  104, 

1881.  W.  mid  Sp.  ;  llevisioii  Paltcocr.,  Part  II.,  p.  Ill  (Proceed.  Aend.  Nat.  Sci.,  Pliila.,  p.  2SS). 

1385.  W.  and  Sp. ;  Revision  Pateocr,,  Part  III.,  p.  104  (Proceed.  Acad.  Nat.  Sci,,  Pliila.,  p.  320). 

1889.  S.  A.  Millkr;  N.  Aiiicr.  Gcol.  and  Palroont.,  p.  259. 

Calyx  obconical,  in  general  aspect  resembling  Gli/ptocnnns ;  intcrradial 
and  interdistichal  spaces  large  and  more  or  less  depressed ;  the  posterior 
interradius  distinguished  by  having  three  plates  in  the  second  row;  the 
plates  of  the  rays  marked  by  a  strong  longitudinal  ridge. 

Basals  four,  small,  almost  of  uniform  size.  The  one  facing  the  anterior 
side  a  little  the  largest  and  pentangular,  the  others  irregularly  quadrangular. 
Radials  and  costals  of  similar  size;  costals  two,  the  first  hexagonal.  Dis- 
tichals two  to  four.  The  palmars,  of  which  generally  the  proximal  plate 
only  takes  part  in  the  calyx,  support  the  arms.  Arms  composed  of 
cuneifo.-m  pieces,  which  either  remain  simple,  or  give  off  a  few  branches 
to  one  side.  Pinnules  given  off  from  opposite  sides.  Interbrachials  rather 
numerous;  anal  side  a  little  wider,  and  containing  additional  plates.   Ventral 

30 


ll 


282 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


disk  flat;  composed,  so  far  as  observed,  of  very  minute,  irregular  pieces, 
apparently  without  oral  plates.  Anus  excentric,  opening  out  directly  through 
the  tegnien.  Column  round ;  axial  canal  of  medium  size,  and  obtusely  pent- 
angular. 

Dldribution.  —  Upper  Silurian  of  Amerisa,  England,  and  Sweden. 

Remarks.  —  Ilall  in  proposing  this  genus  made  "  Mariacrinus  "  mhilissimus 
the  type  of  a  genus,  which  in  all  essential  characters  agrees  with  Mclocrinm 
Goldf.,  notably  in  the  arm  structure ;  the  arms  being  given  olf  from  the 
sides  of  tubular  appendages.  Among  the  species  referred  by  Hall  to  Maria- 
crinus were  some  with  a  very  different  arm  structure,  and  in  1881  we  recon- 
structed the  genus  with  Mariacrinus  plumostis  and  M.  Carkyi  as  types.  The 
genus,  as  we  proposed  it,  includes  only  those  species  with  four  basals  in 
which  the  arms  are  given  off  directly  from  the  calyx. 

Zittel  regards  Mariacriiim,  as  typified  by  M.  nobilissimus,  as  a  synonym  of 
Ctcmcriiius  Bronn,  in  which  we  agree ;  but  the  latter  genus,  according  to 
Sehultze,  *  is  identical  with  Melocrinus. 

Mariacrinus  macropetalus  Hall  is  probably  a  Cori/mhocrinus  Angelin ;  Maria- 
crinus stuloniferus  Hall  is  described  from  fragmentary  columns.  GI>/piocrinus 
Ilarrisi  S.  A.  Miller,  which  we  erroneously  referred  to  Mariacrinus,  not 
knowing  it  Imd  an  anal  plate  between  the  radials,  has  been  transferred  to 
Compsocrinus.  Mariacrinus  granulosus  S.  A.  Miller  is  too  fragmentary  for 
identification,  but  certainly  belongs  to  a  very  different  group. 

Mariacrinus  Carleyi  (Kali,). 
Plate  XXII.  Figs.  Sa,  h,  c. 

1863.    Gli/ptoerimis  C<7%i  —  TUti, ;  Trans.  AUinny  Inst.,  Vol.  IV.,  p.  203;  also  28th  Rep.  N  Y.  State 

Mu9.  Nat.  Hist.,  1375,  p.  132,  Plate  14,  Figs-  7-10. 
1881.     Glyptocrinus  Carleyi  —  IIall;  11th  Ann.  Geol.  Rep.  Indiana,  p.  261,  Plate  13,  Figs.  7  to  11,  and 

Plate  15,  Fig.  6. 
1881.     Mariacrinus  Carleyi — W.  and  Sp.  ;  Revision  Palteoer.  Part  II.,  p.  116. 

Calyx  obconical,  higher  than  wide ;  the  sides  distinctly  convex,  section 
across  the  costals  sharply  pentagonal,  and  across  the  distichals  decagonal ; 
the  radials  marked  by  very  prominent  rounded  ridges;  the  interradial  spaces 
depressed.  Narrower  and  more  angular  ridges  pass  out  to  the  sides  of  the 
radials,  where  they  meet  with  others  from  the  interbrachials,  dividing  the 
surface  of  the  dorsal  cup  into  numerous  triangular  depressed  areas,  which 

*  Monogr.  Echinod.  Eifler  Kalk.,  p.  61. 


^}4 


i^ii! 


MEL0CRINID7E. 


283 


are  thickly  covered  with  fine  granules,  procluci/ig  n  most  beautiful  onitv 
mentution. 

Basalt  small,  forming  a  short  cup;  the  columnar  attachment  small;  the 
axial  canal  pentalobate.  Radials  and  costals  large,  as  wide  as  long.  Dis- 
tichals  two  or  3  X  10,  somewhat  smaller.  Palmars  three  to  four  in  the  calyx, 
decreasing  in  length  upwards ;  the  upper  plates  of  the  two  inner  divisions 
axillary,  supporting  two  arms,  tho^e  of  the  outer  divisions  quadrangular, 
bearing  a  single  arm  from  the  calyx.  Arm  openings  thirty,  diiectod  up- 
wards and  not  visible  from  a  side  view ;  the  arms  are  not  preserved  in  any 
of  the  specimens.  Interbrachials :  1,  2,  3,  3,3;  followed  by  other  minute 
pieces,  which  pass  into  the  disk.  Anal  side  wider :  1,  3,  4,  4,  etc. ;  the  first 
plate  larger  than  the  corresponding  plate  of  the  other  sides,  and  there  being 
no  anal  ridge.  Ventral  disk  very  short,  almost  flat;  the  interambulacral 
spaces  depressed.  Surfiice  covered  by  hundreds  of  very  minute  pieces  with- 
out orals,  the  plates  being  so  small  as  to  be  readily  taken  for  mere  granules. 
Anus  excentric,  placed  at  the  summit  of  a  small  protuberance.  Column 
unknown. 

Horizon  and  Locality.  —  Niagara  group;  Waldron  and  Hartsville,  Ind. 


18SS. 


Mariacrinus  Warreni  Rinoueberg. 
Plate  XXII.  Fiff.  I. 

RiNOUEBEno ;  Proceed.  Acad.  Nat.  Sei.  Pliila.,  p.  133,  Plate  7,  Fig.  4. 


Of  the  type  of  M.  Carleyi,  but  having  two  distichals  instead  of  three,  and 
no  palmars  in  the  calyx.  It  also  diflers  from  that  species  in  the  details 
of  its  ornamentation.  Calyx  obconical,  slightly  contracted  above  the  second 
costals.  Radial  ridges  rounded,  wide  and  quite  prominent ;  the  surface  finely 
corrugated ;  and  there  are  series  of  smaller  transverse  ridges  meeting  those 
from  the  interbrachials. 

Basals  four,  forming  a  conical  cup.  Radials  and  costals  comparatively 
large,  wider  than  high.  Distichals  two,  rather  small.  Palmars  two  or  three 
in  the  calyx;  in  form  resembling  arm  plates,  but  longer.  Arms  twenty; 
long,  slender,  tapering  gradually  to  a  sharp  point ;  the  joints  short,  quad- 
rangular ;  their  upper  and  lower  faces  almost  parallel.  Pinnules  delicate, 
long,  closely  packed  ;  composed  of  joints  twice  as  long  as  wide.  The  arrange- 
ment of  the  interbrachials  cannot  be  accurately  ascertained  from  the  speci- 
men, but  it  is  apparent  that  the  proximal  plate  at  all  sides  rests  upon  the 


■    1 


284 


THE  CRINOIDEA   CAMERATA  OF  NORTH  AMERICA. 


Ill 


sloping  upper  faces  of  two  radials.  Neither  is  anything  known  of  the  con- 
.struction  of  the  disk.  Cohimn  round,  of  moderate  size,  slightly  tapering 
downwards ;  near  the  calyx  the  nodal  joints  are  somewhat  larger  than  the 
internodal  ones,  but  at  a  length  of  about  three  inches  all  joints  are  of  nearly 
equal  size. 

Ilorkon  and  Localit//.  —  Niagara  shale ;  Lockport,  N.  Y. 

Tt/pe  in  the  collection  of  Dr.  Eugene  Ringueberg,  Lockport. 

Mariacrinus  plumosus*  Hall. 
Piaic  XXIII.  Figs.  6  and  7. 

1859.    Hall;  Puliront.  New  York,  Vol.  III.,  p.  110,  Plate  3,  Figs.  6-11. 
1881.     W.  mid  Sp.  ;  Uevisiou  raltcucr.  Part  II.,  p.  116. 

A  small  species.  Dorsal  cup  apparently  obconical ;  the  surface  orna- 
mented by  strong  radiating  ridges,  proceeding  from  the  centre  of  the  plates 
to  adjoining  ones.  Basals  about  as  long  as  wide.  Kadials  a  little  longer 
than  wide.  Costals  nearly  as  large  as  the  radials  and  of  similar  form.  Dis- 
tichals  3  X  10,  eacli  row  supporting  two  arms,  twenty  in  all.  Arms  simple, 
rather  long,  composed  of  slightly  cuneate  joints.  In  the  two  outer  arms,  the 
second  joint  gives  off  a  pinnule  to  the  outer  side,  the  third  is  a  hypozygal 
joint,  and  the  fourth  gives  off  the  second  pinnule  at  the  inner  side;  all  suc- 
ceeding joints  being  pinnule-bearing.  The  two  inner  arms,  according  to 
Hall,  support  no  pinnules  up  to  the  eighth  joint,  but  this  needs  confirmation, 
luterbrachials,  1,  2,  2,  2.  The  arrangement  of  plates  in  the  anal  interradius 
and  construction  of  the  ventral  disk  unknown.  Column  round,  compara- 
tively large. 

Ilorkon  and  LocalUy. — In  the  shaly  layers  of  the  Pentamerous  limestone, 
Wheelock's  Hill,  Litchfield,  Herkimer  Co.,  N.  Y. 

(?)  Mariacrinus  ramosus*  Hall. 

1839.    Hall  ;  Palieont.  New  York,  Vol.  III.,  p.  147,  Plate  2,  Fig.  6. 
18S1.     W.  and  Sp.;  Revision  Palseocr.,  Part  II.,  p.  116. 

Dorsal  cup  urn-shaped,  the  rays  marked  by  strong  ridges,  which  pass  into 
the  arms.     Basals  small.     Eadials  and  costals  higher  than  wide.     Distichals 

*  We  are  somewliat  in  donbt  as  to  the  generic  relations  of  this  spceics,  and  think  it  possible  from  Hall's 
fi^nre  lliat  it  may  possess  infinbasnls,  and  therefore  belong  to  a  different  genus.  We  do  not  reproduce  the 
(iriginiil  figure,  because  it  does  not  agree  with  the  description,  cither  in  the  arrangement  of  the  plates  in  the 
calyx,  or  the  construction  of  the  arms.  We  had  no  opportunity  to  see  the  typo  specimen,  and  only  can  give 
an  abstract  of  Hall's  description. 


^ 


:i- 

r 

! 

! 

i"  ■ 

1 

;.  t. 

/f 


MELOCRINID^. 


285 


3  X  10,  each  serio?  supporting  two  arms,  or  twenty  from  the  calyx.  Tlie 
two  inner  arms  branch  three  times,  the  outer  ones  reuuiin  simple.  Above 
the  lust  bifurcation,  according  to  Hall,  the  arms  are  composed  of  a  "  double 
serico  of  wedge-formed  plates,  and  below  these  points  of  a  simple  series  of 
quadrangular  plates,"  with  rounded  pinnules. 
Horizon  and  Locality.  —  Same  as  last. 


l! 


Mariacrinus  aureatus  S.  A.  Miller. 

(After  Miller.) 
1801.    Adv.  Sheets  17th  Rep.  Geol.  Surv.  of  Indiana,  p.  34,  Plate  6,  Fig.  36. 

Calyx  very  small.  Dorsal  cup  bowl-shaped ;  plates  covered  with  angular 
ridges  passing  out  from  their  centres.  Basals  four,  unequal ;  exposed 
beyond  the  column.  Radials  the  largest  plates  of  the  calyx,  wider  than 
high.  First  costals  a  little  smaller,  their  width  greater  than  the  length ; 
pentangular  or  hexangular.  Second  costals  as  long  as  wide.  Distichals  two 
in  the  three  anterior  rays,  three  in  the  posterior  ones ;  the  second  plate  of 
the  former  axillary.  Interradial  areas  elongate,  subovate.  Regular  sides 
composed  of  seven  or  eight  plates :  1,  2,  2,  2  ;  the  first  nearly  as  large 
as  the  radials.  Interdistichals  one  or  two.  Tlie  anal  side  has  nine  or  ten 
plates,  there  being  three  in  the  .second,  and  four  in  the  third  row;  the  plates 
of  the  upper  row  very  small.  Arm  structure  and  tegmen  not  preserved  in 
the  specimens. 

Horizon  and  Localiti/.  —  Niagara  group ;  St.  Paul,  Ind. 


r 


MACROSTTLOCRINUS  Hall. 

1852.  Hall;  Piilicont.  N.  York,  Vol.  II.,  p.  203. 

1S57.  PiCTET;  Traite  de  Pnleoiitolngie,  Vol.  IV.,  p.  329. 

1802.  DujARDiN  and  Hupe;  Hist,  ualiir.  dcs  Zoopli.  Ecliin.,  p.  149. 

1863.  Hall  ;  Trans.  Alb.  Inst.,  Vol.  IV.,  p.  207  (Abstr.  p.  12). 

1879.  Hall;  Mus.  edit.  28th  Rep.  N.  Y.  State  Mus.  Nat.  Hist.,  p.  128. 

1879.  Zittk.l;  Handb.  d.  Pala-ont.,  Vol.  I.,  p.  308. 

1881.  W.  and  Sp. ;  Uevision  I'nlaiocr.,  Part  II.,  p.  102 ;  also  Proceed.  Acad.  Nat.  Sci.  Phila.,  p.  270. 

1881.  Hall;  lllh  Ann.  Rep.  Geol.  of  Oliio,  p.  256. 

1882.  Ringuederg;  Joiirn,Cinein.  Soc.  Nat.  Hist.,  Vol.  V.,  p.  119. 

1882.  JjE  Loiuol;  Paleont.  Fran9aisc,  Tome  XL,  Crinojdcs,  p.  50. 

1883.  W.  and  Sp. ;  Revision  Palaiocr.,  Part  III.,  p.  102;  also  Proceed.  Acad.  Nat.  Sci.  PIiila.,p.  324. 
Syii.  Actiiiocriiiusi  (in  part)  —  Lvon;  Proceed.  Acad.  Nat.  Sci.  Phila.,  1801,  p.  411. 

Syn.  Cijathocrinm  (in  part)  —  Hall;  Doc.  edit.,  2StU  Vol.,  N.  Y.  State  Mus.  Nat.  Hist.  (Explana- 
tion of  Plate  13). 
Sjn.  Clenocrims  (in  part)  —  Suumard;  Trans.  Acad.  Sci.  St.  Louis,  Vol.  II.,  p.  360. 


286 


THE  CRINOIDKA  CAMERATA  OF  NORTH  AMERICA. 


Specimens  small.  Calyx  obconical  to  subglobose ;  generally  with  promi- 
nent rklges  along  the  radial  and  anal  plates  j  the  surface  densely  coverod 
with  very  fine  striaa  or  small  granules. 

Basals  three,  large,  unequal,  forming  a  more  or  less  deep  cup ;  two  of 
the  plates  equal,  the  other  one  half  smaller.  Radials  very  large ;  their  upper 
corners  but  slightly  truncated  by  the  interbrnchials.  Costals  two,  small ; 
rarely  more  than  one  third  the  size  of  the  radials,  and  in  some- species  still 
smaller.  Of  the  distichals  genendly  only  the  first  jjlatc  takes  part  in  the 
calyx,  but  occasionally  also  the  second.  Arms  ten,  long,  biserial,  and  simple 
throughout.  Interbrachials  few.  Anal  area  much  the  widest  and  quite 
distinct.  It  has  three  plates  in  the  first  row,  of  which  the  middle  one  is 
placed  against  the  sloping  upper  faces  of  the  two  posterior  radials;  while 
the  two  smaller  ones  at  the  sides,  together  with  the  first  costal,  occupy  the 
upper  face  of  the  plate,  in  a  similar  manner  as  the  corresponding  plates  of 
the  PlatycrinidaB,  except  that  those  of  Macrostylocriinis  do  not  extend  beyond 
the  limits  of  the  dorsal  cup.  The  middle  or  anal  plate  is  generally  followed 
by  one  or  two  other  anals,  longitudinally  arranged.  Ventral  disk  low;  com- 
posed, so  far  as  observed,  of  small  irregular  pieces.  Column  round ;  axial 
canal  small. 

Distribution.  —  Restricted  to  the  Niagara  group  of  America. 

Tyjie  of  the  genus :  Macrostyloerimis  ontutus  Hall. 

HemarJcs.  —  This  genus  differs  from  all  other  Melocrinites  in  the  number 
of  basals,  and  in  having  in  the  anal  interradius  three  plates  in  the  first  row, 
while  the  others  have  but  one.  The  anal  side  of  Hall's  diagram  on  page  130 
of  the  28th  Rep.  N.  Y.  State  Museum  is  incorrectly  given,  and  it  appears 
from  the  description  that  Hall  was  not  aware  that  in  Macrostylocrinus  the 
arrangement  of  plates  in  the  anal  interradius  differs  from  that  of  the  other 
sides.  The  basals  in  that  diagram  are  represented  a.s  equal,  while  in  fact 
they  are  unequal,  two  of  them  being  larger  than  the  third. 

Shumard  regarded  this  genus  as  identical  with  Ctenocrinus  Bronn,  from 
which  it  differs  in  the  construction  of  the  anal  interradius  —  the  latter 
having  but  one  plate  in  the  first  row  —  and  also  in  the  number  of  basals. 

MacrostyloorinuB  ornatus  Hall. 
Plate  XXIII.  Figs.  8a,  h,  c. 

1851.     Macroslylocrinus  ornatus  —  IIai.l  ;  Pulocoiit.  N.  Y.,  Vol.  II.,  p.  204,  Plate  46,  Figs.  ^a-g. 
1S66.     Ctenocrinus  ornatus  —  Shumakd;  Trans.  Acad.  Sei.  St.  Louis,  p.  301. 
1881.    Macrostylocrinus  ornatus  —  W.  and  Sp.  ;  licvisiou  Pulieocr.,  Part  II.,  p.  103. 


MELOCRINIDiE. 


287 


Dorsal  cup  about  as  high  as  wide ;  cross-section  siibpentangular ;  tlio 
median  portions  of  the  basals  and  costals  slightly  elevated ;  their  surfaces, 
and  those  of  the  radials,  covered  with  fine,  interrupted  strioc,  and  the  inter- 
brachials  with  elongate  tubercles,  which  at  the  centre  of  the  plates  become 
obsolete.     The  suture  lines  well  defined. 

Basals  not  as  large  as  in  some  of  the  other  species,  forming  a  shallow 
basin  with  obtuse  upper  angles.  Eadials  more  than  twice  as  large  as  the 
costals,  slightly  spreading ;  the  upper  faces  somewhat  shorter  than  the 
lower  First  costals  hexagonal,  their  upper  sloping  faces  much  shorter  than 
the  sloping  lower  ones ;  the  second  costals  smaller  than  the  first,  the  upper 
side  obtusely  angular.  Distichals  free  above  the  first ;  the  three  proximal 
plates  quadrangular,  the  edges  of  their  upper  and  lower  faces  crenulatcd ; 
the  succeeding  three  or  four  plates  cuneate,  and  the  plates  above  interlocking 
so  as  to  form  two  rows  of  arm  plates ;  the  latter  covered  by  two  rounded 
tubercles,  transversely  arranged,  and  placed  in  rows  longitudinally.  Arms 
ten,  long  and  rounded.  Regular  interbrachials  three  known ;  the  lower 
plate  twice  as  large  as  the  two  upper ;  the  latter  resting  against  the  sides  of 
the  second  costals,  slightly  touching  the  first.  All  other  parts  of  the  species 
unknown. 

Horizon  and  Localifi/.  —  Shales  of  the  Niagara  group ;  Loekport,  N.  Y. 

liciiiarJis.  —  We  have  been  imable  to  trace  the  type  specimen,  and  our 
description  was  made  from  Hall's  figure  in  the  New  York  Report. 


J^ 


Macrostylocrinus  striatus  Hall. 
Plate  XXII.  Figs.  14a,  b,  c. 

1863.  Ham.;  Trans.  Alb.  lust.,  Vol.  IV.,  p.  207  (iibstr.  p.  13). 

ISfiB.  Siii'Mard;  Trans.  Acad.  Sci.  St.  Louis,  Vol.  II.,  p.  361  {Clenocriims  striatus). 

1870.  Hall;  28tli  Rep.  N.  Y.  State  Mus.  Nat.  Hist.  (.Museum  edit.),  p.  129,  Plate  13,  Figs.  1-4. 

1881.  \V.  and  Sp.;  Revision  Palajocr.,  Part  II.,  p.  103. 

ISSiJ.  Hall;  11th  Ann.  Rep.  Geol.  and  Nat.  Hist.,  Oliio,  p.  257,  Plate  12,  Figs.  1-4. 

Calyx  to  the  bases  of  the  arms  pyramidal ;  the  sides  slightly  convex ;  the 
fixed  brachials  formed  into  broad  rounded  ridges,  which  pass  up  to  the  arms ; 
interradial  spaces  somewhat  concave,  except  at  the  anal  side  where  the 
median  portion  is  slightly  bulging  and  angular.  Surface  of  plates  covered 
by  fine  undulating  striae  or  series  of  granules,  about  twelve  of  which  traverse 
the  lower  half  of  the  radials  to  the  basals;  another  set  passes  up  to  the 
costals,  and  a  third  and  fourth  transversely  to  the  sides  of  adjoining  radials. 


!^:f 


288 


TIIK  CRINOIDEA  CA5IKRATA  OF  NORTH  AMERICA. 


Eiieh  lino  of  the  transverse  sets  meets  one  of  the  longitudiniil  lines  at  riglit 
angles  or  less,  and  the  apices  of  these  angles  lull  into  lines  from  the  centre 
to  the  corners  of  the  plates. 

Basuls  large,  forming  a  flat  basin;  column  facet  small  and  slightly  pro- 
jecting ;  the  upper  margins  distinctly  pentangular.  Kadials  large,  even  for 
the  genus.  Costals  ciu'ved  like  arm  plates;  the  first  less  than  one  fourtii  the 
size  of  the  radials.  The  fust  palmar,  which  bends  slightly  outward,  included 
in  the  calyx.  Structure  of  arms  unknown,  but  there  were  apparently  two 
arms  to  the  ray.  Interbrachials  in  two  ranges,  composed  at  the  regular 
sides  of  one  plate  each,  of  which  the  second  is  considerably  smaller.  The 
anal  side,  which  is  much  wider,  is  composed  of  three  plates  in  the  first 
row ;  the  median  one  larger  and  wedged  in  between  the  sloping  sides  of 
the  radials ;  the  second  range  consists  of  five  smaller  plates,  irregularly 
arranged,  and  followed  by  still  smaller  pieces. 

Horizon  and  Locality.  —  Niagara  group  ;  Waldron  and  Hartsville,  Ind. 

Remarks.  —  This  species  is  allied  to  M.  ormiliis,  but  differs  in  the  propor- 
tions of  the  plates  and  the  absence  of  radial  ridges.  The  specimen  figured 
by  Hall  in  the  20th  Rep.  of  N.  Y.  State  Cabinet  on  Plate  10,  Fig.  7,  under 
M,  striafiis,  seems  to  us  to  differ  essentially  from  that  species  in  the  propor- 
tions of  the  plates,  and  may  oven  belong  to  a  different  genus. 

Maorostyloorinus  fasoiatus  Hall. 
Plate  XXII.  Fi(j.  13. 

1S7C.     Cyathocrinui  faseiatu>  —  'nK\.\.;  Doc.  edit.  28tli  Hep.  N.  \.  Sln:c  Museum  Nat.  Hist.,  Plate  13, 

Figs.  5  aiid  0  (without  description). 
1879.     Maerostyloniiius  fiisria/in  —  IIai.i.;  .Mus.  edit,  of  same  Kop.,  p.  130'  mid  lltli  Ann.  Rep.  Gcol. 

and  Nat.  Hist.  Ohio,  1882,  p.  238,  Plate  12,  Figs.  5  and  0. 

Calyx  subovoid  ;  height  to  width  as  ten  to  seven ;  rounded  to  two  third.s 
the  length  of  the  radials,  cylindrical  above  ;  arm  bases  but  little  projecting  ; 
ventral  disk  almost  flat.  Surface  of  plate.s  densely  covered  b^-  fine,  waving 
striae,  which  radiate  in  fascicles  from  the  basals  to  a  place  a  little  above  the 
centre  of  the  radials,  whence  other  bundles  pass  out  to  the  intcrbrochials 
and  adjoining  radials.  In  addition  to  the  8tria3,  the  surface  is  marked  by 
indistinct  ridges,  which  follow  the  median  line  of  the  fascicles,  and  produce 
a  well  defined  stellate  prominence  upon  the  basal  cup  and  upon  each  radial 
and  first  interbrachial  plate.  The  ridges  upon  the  costals  are  the  most 
prominent,  and  increase  in  width  on  approaching  the  arm  bases. 


MELOCRINID^E. 


289 


Biisuls  largo,  forming  a  roundod  cup,  with  a  narrow  coliuiinar  ivttochtncnt. 
Riuliiils  unuHually  largo,  I'ully  four  tiuics  the  size  of  the  cowtnls,  and  about 
three  times  as  long;  very  little  sloped  to  meet  the  first  interbrachial.  First 
costala  somewhat  larger  than  the  second.  The  two  proximal  paiinars  incor- 
porated into  the  calyx,  the  others  free.  Arms  ten.  Interbrachials  compar- 
atively small,  one  and  two  at  the  regular  sides;  the  nnal  side  wider,  and 
composed  of  three  plates  in  the  first  row.  Ventral  disk  constructed  of  small 
irregular  pieces. 

Horizon  and  Locnlity.  —  Same  as  last. 

Remarks.  —  Hall's  figures  5  and  6,  on  Plate  13  of  the  28th  Rep.  N.  Y. 
State  Museum,  are  incorrect  and  misleading.  The  first  costals  are  represented 
twice  as  large  as  they  actually  are,  and  the  ornamentation  is  also  somewhat 
different  in  the  specimens.  In  the  20th  Rep.  of  the  same  series,  Plate  10, 
Fig.  1,  Ilall  figures  a  cast  from  the  Niagara  group  of  Racine,  Wise,  described 
on  page  379  under  the  name  o?  Actinocrlnvn  (Saccocrinus)  semiradkUts,  which 
may  possibly  bo  a  large  example  of  this  species. 

Maorostyloorinus  granulosus  (Hall), 
Plate  XXII.   Figs,  loa,  h. 

1879.    Maeroslflocriiiui  itriatus,  vnr.  granutoiu)  —  Uall;  28iIi  Ucp.  N.  Y.  State  Mus.  Nut.  Hist.  OIu- 

scum  edit.),  p.  129. 
1885.    M.  atrialus,  XM.  granulosus  —  W.  and  Sp. ;  Ucvisiou  ralivocr.,  I'nrt  III.,  p.  102. 

A  more  slender  species  than  the  preceding.  Dorsal  cup  obconical ;  its 
sides  nearly  straight,  .spreading  gradually  and  uniformly  upwards ;  cross- 
section  at  the  top  of  the  costals  decidedly  pentangular ;  the  basals  and  nil 
plates  following  the  rays  marked  by  broad,  rounded  ridges.  Another  promi- 
nent ridge  pas.sos  from  the  anus  downward  to  the  middle  of  the  proximal 
anal  plate,  where  it  bifurcates  to  adjoining  radials.  Narrower  ridges  connect 
the  radials  laterally,  and  form  a  well  defined  boimdary  line  between  the 
upper  and  lower  portions  of  the  dorsal  cup.  The  general  surface  is  covered 
by  fine  wrinkles  and  indistinct  striae ;  those  following  the  radials  and  costals 
longitudinally  arranged,  the  others  meeting  within  the  middle  of  the  plates. 

Basals  and  radials  smaller  than  in  the  preceding  species  ;  the  latter  plates 
about  as  wide  as  long,  subquadrangular,  and  but  very  little  sloped  at  the 
upper  corners.  First  costals  less  than  two  thirds  the  length  of  the  radials, 
and  considerably  narrower;  second  costals  shorter  and  narrower  than  the 

37 


( 


290 


TIIK  CUINOIDEA  CAMKRATA  OF   NOllTII   AMKRICA. 


fivnl,  thuir  iippor  iiiiyles  nciito.  Arms  two  to  the  ray,  ireo  above  the  firxt 
plutu,  wliieh  is  longer  tliun  wide.  The  nriiiH,  nccording  to  Hull,  arc  long, 
blender,  and  simple.  Regular  interbrachiuis  slightly  convex  ;  arranged  :  1, 
2,  ;].  Anal  iiiternidius  much  wider,  composed  of  three  plates  in  the  first 
range  ;  the  middle  or  anal  plate  longer  than  the  two  at  the  sides  and  fol- 
lowed by  a  second  anal  piece,  of  which  the  top  is  on  a  level  with  the  top  of 
tiio  interbrachials  of  the  third  range.     Structure  of  ventral  di.>'k  unknown. 

Ilorkon  and  Loculitij.  —  Same  ns  last. 

Jieinarks.  —  Prof.  Hall  uuide  this  species  a  variety  of  M.  ulriatits.  It  is, 
however,  suflicienlly  different  to  be  recognized  as  a  distinct  species,  which 
we  believe  is  more  nearly  related  to  M./aseiuhis  than  to  M.  striutus. 

MaorostylQorinuB  Meeki  (Lvun). 
Flute  XXII.   Fi</a.I6a,b. 

ISOl.     Aetinocrhm  Meeki  —  I.vox  ;  I'rocced.  Acad.  Nut.  Sci.  I'ljiln.,  p.  411,  Plntc  4,  Figs,  ia,  b. 
1S81.    Macrosl^lucriiim  Meeki  —  \V.  mid  Si'.  ;  llcvisiuii  I'nla'ocr,,  I'lirl  II.,  p.  103. 

Calyx  subglobose,  about  as  wide  as  high ;  cross-section  slightly  pentangu- 
lar. A  well  defined  ridge  rises  from  the  column,  follows  the  median  lino  of 
tiie  various  radial  plates,  and  passes  into  the  arms.  The  rie,  which  is 
ratlier  obscure  upon  the  basal."*,  gradually  increases  in  size,  and  grows  quite 
prominent  upon  the  costal^*.  Smaller  ridges  proceed  from  the  centre  of  the 
radials  to  the  interbrachials,  and  form  with  tlio  larger  ridges  numerous 
obscure  triangles.  The  inner  spaces  of  these  triangles  are  occupied  by  fine 
closely  arranged  striae,  which  form  additional  triangles  one  within  the  other ; 
there  being  five  such  sets  of  triangles  around  the  column,  which  extend  to 
the  middle  of  the  radials,  and  are  larger  and  better  defined  than  any  of  the 
others. 

Basals  forming  a  shallow  basin,  rounded  at  the  bottom  ;  the  column  facet 
slightly  concave.  Radials  fully  four  times  as  large  as  the  first  costals,  and  as 
long  as  wide.  First  costal  narrower  than  the  second,  and  fully  twice  as  wide 
as  long;  the  second  somewhat  larger,  its  sides  spreading  rather  abruptly 
upwards,  the  sloping  upper  faces  concave  and  forming  an  acute  angle.  First 
interbrachial  large,  a  little  longer  than  wide,  resting  against  the  distinctly 
sloping  !<ides  of  the  radials,  and  rising  to  the  top  of  the  second  costals ;  the 
succeeding  plates  much  smaller.  The  arrangement  of  plates  at  the  anul  side 
is  not  known ;  neither  is  the  construction  of  the  ventral  disk  nor  the  struc- 
ture of  the  arms. 


MKI.OCRINID.E. 


291 


Ilorhon  and  LnrdHh/.  —  Ningara  group ;  .TcfTcrxon  Co.,  Ky. 
TiJiiiH  in  tho  Knapp  collection  at  the  Borden  InHtitutu  of  New  Provi- 
dence, Ind. 

MaoroBtyloorlnus  AiBibraohiatus  UiKnrEnp.Ro. 
Plate  XXIII.  Fiifs.  9  &  10. 

1891.    BiNoi'Ernno ;  Jdiirii.  Ciiiciu.  Snc.  Nat.  Ili»t,,  Vol.  V.,  p.  110,  Plato  S,  Fiff.  1. 
1885.     W.  iiJiil  Si'. ;  Uevi«i(>ii  ralitocr.,  I'lirt  111.,  p.  10*. 

Larger  than  the  preceding  species,  and  proportionally  broader.  Dorsal 
cup  apparently  bowl-shaped  —  tho  exact  form  not  being  ascertainable  owing 
to  the  crushed  condition  of  the  specimen  ;  interradial  spaces  depressed  ;  sec- 
tion subpentagonal ;  surface  of  plates  covered  by  numerous  small,  irregu- 
larly arranged  granules. 

Basals  of  moderate  size,  forming  together  a  rapidly  spreading  pentagonal 
cup  ;  the  column  facet  surrounded  by  a  small  rim,  formed  by  a  row  of  sninll, 
closely  arranged  nodes.  Radials  large,  wider  above  than  below,  subtiuad- 
rangular;  the  upper  corners  slightly  truncate.  First  costals  quadrongular, 
less  than  half  the  size  of  the  radials,  nearly  twice  as  wide  as  long.  Second 
costala  smaller  than  the  first,  and  considerobly  shorter.  Distichals  free  after 
the  second  plate.  Arms  ten,  long,  massive,  widest  in  tho  middle,  and  taper- 
ing at  both  ends.  The  two  fixed  distichals  are  followed  by  a  few  much 
shorter  cuncate  pieces,  and  the  latter  by  two  rows  of  short  transverse  ])lates, 
alternately  arranged  and  united  by  a  zigzag  suture.  Regular  interbrachials 
five  in  three  ranges ;  the  first  plate  large  and  oblong ;  the  arrangement  of 
tho  anal  side  unknown.  Column  round ;  the  edges  of  the  nodal  joints  sur- 
rounded by  small  nodes. 

Horizon  and  Loccditi/,  —  Niagara  group  ;  Lockport,  N.  Y. 

T/jpe  in  the  collection  of  Dr.  E.  N.  S.  Ringueberg. 

Remarks.  —  The  specimen  illustrated  by  Fig.  10  differs  slightly  from  the 
type,  being  smaller,  and  having  a  more  elongate  cup,  less  massive  arms, 
and  proportionally  higher  costals.  But  as  it  is  of  the  general  habitus  of 
this  species,  we  take  it  to  be  a  young  specimen  of  the  same. 


I:      I 


39S 


THE  CUINOIDEA  CAMEUATA  OF  ^UK^H  AMElllCA. 


MELOORINUS  GuLoru**. 

ISiO.    CJiiLDrrMi  IVtrt'f.  (itTiiiniiiir,  Vol.  I,,  |i.  107. 

It.'IS.     AiiAKSI/.  1   Mi'iii.  ilr  lit  Sue.  (Ii'»  t<n.  iiiiliir.  di'  Ncuclmli'I,  Vnl.  I.,  p   I'Jfl 

IHMS.    (ioi.nniM  i  Ndvii  A'iii,  Anul.  l,iMi|iiililiim,  V(il.  XIX,,  1,,  ji.  33tf. 

IMl.     MCi.i.KHi  MdiiiiUlxr.  il    llirliii.  Akiidiniii',  p.  <()U. 

iHtO.     D'OiiiiKiNy  ;  Cmrn  ('li'mciit.,  Vol.  II.,  p.  I  M). 

Uii.    Qiknutkut;  IIiiimH)  >I.  IVlirl'iii'liiikuiiili'  (Aii«i;.  I  ),  \>.iVii). 

18.55.     Kokmkk;  I.clliiirn  (icoKiio'ilica  (Aio^.  II).  p.  i'M. 

IS.'JT.     I'ktp.T!  Triiilodu  I'al.'oiil.,  Vol  IV.,  p.  .U'J. 

1802.    DrjAiiDi.H  uiiil  Uvvi:;  llUt,  imliir.  iUh  /.oophyiivi,  p.  lit. 

1807.     S(  IIDI.TZK;  Moiionr.  Kc'hinoil,  Kill.  Kiilk,,  p.  «1. 

18*8.     Amiki.in;  Iniiioitr.  Criii.  Sure  ,  p,  19. 

1S70.     /ITTKI,;   llaihlli.  il.  I'uliroiit.,  Vol.  I.,  p.  371. 

1S81.     W.  mid  Sp.  ;  IVonrd.  Arad.  N»l,  S,i,  I'hilii  ,  p,  202 

1881.     W.  mid  8i'. ;  Urvl-ioii  I'aliincr .  Part  II.,  p.  U^. 

1881.     Dl  Ldiiloi.;  I'alroiit.  Friiiiviiiii',  Toiiiu  \l.  (Criiioidrn),  p,  89. 

1895.     W.  mid  S\\  ;  I'roc.Til.  Acid.  Nat.  Scl.  I'liila.,  p   iWfl. 

1883.     \V.  imd  Sp.;  Hcvi.tloii  TaWorr.,  Part  111,,  p.  101. 

1885.    Quenstkiit;  llaiidl).  d.  Pi'lri'l'ai'lciikiiiidc  (Aiik|{.  3),  p.  03*. 

1830.     S.  A.  Mil.r.Kit ;  N.  Amcr.  (Iced,  mid  Pal il.,  p.  201. 

8yn.  CleiiiirriiiHS  Hhiinn  ;  IHIO,  .lalirli.,  p.  tvU;  nl»i>  MiilltT,  1S55,  Vcrli.  nnturli.  Vcroiii,  \  ,.1.  XII., 
p.  II),  and  Nuuu  EuliiiKid.  Kill.,  Kalk.,  p.  255  ;  nlao  Follmaiiii,  1857i  UiitcnlcToiilBclio  Crmoidi'cn, 
p  U. 

8yn.  Cdn/iitiocriiiu)  Uokmeii;  1S55,  LpIIi.  OroRii.  Vol.  II.,  p.  252. 

S.vii.  MiiriiiniiiiiH  llvi.r.  (in  pari);  1837,  I'alii'oiit.  N.  Y.,  Vol.  111.,  p.  lOt. 

Svii.  Ci/toiriiim  Kukmkii;  1S(J(),  Silur.  Fniiim  West.  Tonn.,  p.  4(1. 

Sjii.  ('/aiioiriiiiu  Okmlkkt;  1S7'J  (not  Qnriisti'dl),  Soc.  (i*''(d.  dc  Kranrc  (sh.  3),  Vol.  VII.,  p.  9. 

8)11.  THi-hiiiiirriiiilfn  Thoosti   1830,  l,Ut  of  Criii.  Trim,  (not  dt  fined). 

Sjn.  A'IrDi-rimlpfCmKKw;  Ann.  ficol.  Hop.  N.  Y.  of  IHjn  to  1S41  (not  C;inihprlnnd,  1*^20,  nor 
Antlin,  1842,  nor  Kllic'rid({p,  .Inn.,  Is*!),  nor  Anlemerinui  Miiusler,  1839,  nor  Ljon,  lS37,  nor 
.t-i>iocrittm  Ether,  nnd  Carpenter,  ISSO). 

Ciilyx  obconiciil,  siihglobosc  or  pyriform ;  the  rays  extended  into  free 
tubular  nppoiuliigeH  boiiring  arin.s  on  both  sides.  Ba.si\l.s  four,  unequal ;  three 
of  them  (juachangidar,  tlio  anterior  one  Uyger  and  pentangular.  RadiiilH  in 
contiict  laterally ;  four  of  them  heptagomd,  the  anterior  one,  which  rests 
squarely  upon  the  anterior  ba.<fal,  hexagonal.  First  costal  hexagonal,  the 
second,  which  is  axillary,  generally  pentagonal  ;  the  sloping  faces  of  the 
latter  may  be  equal  and  support  two  rows  of  distichals,  or  unequal,  when 
only  the  longer  inner  face  is  foUowed  by  distichals,  the  shorter  outer  one 
giving  off  the  proximal  arm.  In  the  former  case,  which  is  the  general  rule, 
the  distichals  constitute  ports  of  the  calyx,  and  both  series  terminate  in 
axillariea,  which  give  off  foward  the  inner  side  of  the  ray  in  a  nearly  verti- 
cal direction  an  indefinite  number  of  brachials  of  successive  orders,  and 
toward  the  outer  side  a  sloping  arm  from  each  order.  The  plates  of  the 
different  orders  are  short  and  consist  of  two  parallel  series,  which  form  two 
arm-bearing  trunks.     The  two  trunks,  as  a  general  rule,  meet  laterally  by 


I 


&-.%•- 


MKF.OCniNin.K. 


2on 


.* 


■utiti'o,  nn<l  form  togctlicr  rij^iil  tiibiiliir  nppondngof*,  wliifli  piiss  out  iViiiii  tlm 
cn\yK  upwni'ilH.  In  hoimo  ciihuh  tlio  cuniu'ction  of  tliu  nppuiuliig<-s  is  iulii- 
ruptod  for  nliort  (liMtaiiceM,  but,  no  fur  iw  known,  nil  of  them  coim-  tojjollior, 
Bnd  nro  nnitod  towiinl  tin*  nppiT  part.  Fiom  tlicsi!  nppcniliigt-H  tliniii^'lioiit 
tli<'ir  '"»n  length,  lit  ccrtnin  inlcivul.'*,  iinil  from  ojiposito  pliitfH  (nut  nltor- 
Pivtely)  nn*  givon  oil'  wt'il  (IcCiikmI  MHi'iial  arnin,  bearing  piiiniik's  on  altcrnatt' 
Bldcf.i,  A  »<liglit  (li'partnrc  in  tlio  coiiMtrnction  of  tlio  main  trunks  occurn  among 
ppocloH  in  wliicb  tliu  proximal  arms  aru  givon  ofT  alroady  from  tlio  flrxt 
nxillarioH, /.('.,  from  llio  oostaln.  In  tlioso  species  tlio  trunks  nt  tlic  dorsal 
surfaci!  iiro  composud  ofbut  a  winglo  series  of  plates,  and  the  pinnide-bearing 
arms  are  arninifd  alternately  as  in  Shijinincriniin  sml/ihiK.  Tlie  ventral  sur- 
facoM  of  the  appendages  are  roofed  over  in  all  canes  by  rigid  covering  plates. 

Intorbracliials  numerous  ;  the  first  placed  ujjon  the  sloping  upper  faces 
of  tlie  radials,  followed  by  two  plates  in  tlio  second  row  at  the  four  regular 
Bides,  three  plates  at  the  nnal  side,  and  a  greater  or  les-  number  of  irregular 
plates  above,  which  meet  with  the  inteiambulacral  plates.  Ventral  disk 
highly  elevated  or  scarcely  convex ;  tho  orals  In  some  species  largely  de- 
veloped, in  others  indeterminable.  Anus  cxcentric  and  generally  —  jierhapH 
always  —  extended  into  a  small  tube. 

Column  round,  composed  of  alternate  long  and  short  joints ;  axiid  canal 
Hmall. 

Dint rihul ion.  —  Mvlorriniin  ranges  from  tho  Upper  Siluiian  to  near  the 
close  of  tho  Devonian,  and  is  well  represented  both  in  America  and  Kurofie. 

HeDKivks. — The  genus  Mi'lorrinus  holds  the  same  relation  to  Mitrinrrinus 
that  Stc(j'inocruiiis  does  to  Ar/hwrrmus,  and  Fiirhifloen'iiiis  to  Plnl/jcrltiuK.  In 
all  those  typos  tho  construction  of  tho  calyx  remains  relatively  almost  un- 
changed, while  a  remarkable  modification  occurs  in  tho  brachial  appendages, 
which  are  extended  into  tubular  rays  with  an  indefinite  number  of  semi-free 
brachials,  giving  off  arms. 

Several  attempts  have  boon  made  to  subdivide  Melncrimin  into  two  or 
three  genera.  Roomer,  in  1855,  proposed  the  name  CdstdiiocriiiKs  for 
species  with  a  central  or  subcentral  anal  opening,  retaining  Mclnrriinix,  with 
M.  hlern(jbiphicns  Goldfuss  ns  type,  for  species  with  a  lateral  opening.  Our 
examination  of  the  various  species  leads  us  to  doubt  whether  such  a  division 
can  bo  practically  uphold.  We  agree  Avith  Schultze  *  that  tho  anus  is  never 
central  in  this  genus,  nor  in  any  case  actually  lateral,  but  its  position  is 

•  Moiiogr.  Eifl.  Knlkes,  p.  03. 


29i 


THE  CKINOIDKA  CAMERATA  OF  NORTH  AiMERICA. 


1 


always  more  or  loss  excentric.  Neither  can  the  presence  or  absence  of  inter- 
ilistichiils,  unless  accompanied  by  other  distinctive  characters,  be  considered 
sudicient  for  generic  separation,  as  proposed  in  the  case  of  C/eiioeriiius 
Bronn.*  Those  plates  are  mere  auxiliary  pieces,  which  may  be  present 
or  absent  in  the  same  species. 

Tiirhiiiocri'iii/cs  Troost  was  proposed  in  MS.,  according  to  ITall.t  for  a 
species  which  was  said  to  have  the  first  anal  plate  on  a  level  with  the 
radials;  but  Tvoost's  typical  npccics,  JItlocriinis  Venu'inli,  had  no  such  plate, 
or  Hall  could  not  have  stated  that  the  anal  area  was  but  slightly  distinct 
from  tlie  other  four. 

Ci/t'icniiiis  was  described  by  Eoemcr  with  three  (?)  basal  plates  —  the 
exact  number  not  having  been  ascertained.  A  good  specimen  in  our  collec- 
tion from  Roemer's  typical  locality  plainly  shows  four  plates,  and  we  have 
no  doubt  the  species  is  a  Mclocrhms. 

rhiJUjhtitrriniix  McCoy  is  described  with  four  basals,  succeeded  by  seven 
plates  in  the  next  ring,  which  shows  that  it  is  an  abnormal  specimen.  If  it 
is.  as  we  think,  an  Actinocrinoid,  the  abnormal  seventh  plate  may  have 
necessitated   the  presence  of  a  fourth  basal. 

In  addition  to  the  species  herein  figured  and  described,  we  note  the 
following  ;  Melocriinis  ohpyrniuidalis  Winchell  and  Marcy,  M.  Vcrncuili  Hall 
(not  Oehlert).  and  ^^.  mdomis  Hall,  which  were  described  from  unsatisfactory 
natural  casts.  Neither  can  M.  Praltciii  {Forbcsiocriiiiis  Pruffem)  McChesney, 
which  was  defined  from  a  fragmentary  specimen,  or  Mclocrinus  sciilptus  Hall, 
of  whicli  only  tiie  ba.sal  plates  are  known,  or  M.  hrvidacti/lus  Hall,  which 
was  figured  but  not  described,  and  the  figure  not  properly  published,  be 
regarded  as  good  species. 

*  Tlio  fjcinis  Clfaoeriiiiii  was  at  first  incorrectly  defined.  It  was  dcscril)cd  liy  Bronn,  1840  (Jnlirbucli, 
p.  .542),  with  tlirce  b.-isal  pliitos,  and  this  number  was  confirmed  by  llocmer  (liCtliacn  Gcogn.,  1855,  p.  251). 
Subsequi'iilly  dc^  Koninck  considered  tlic  genus  idonticid  witli  Pradocriiiiis  Ue  Vcrnenil,  whicli  actually  lina 
three  basiils.  Job.  Miiller  (,Verhaniil.  niiturb.  Vcrein,  1S5,"))  admits  more  than  three  basals,  probaldy  five, 
,ind  in  ]S.j7  (Neue  Echiuod.  Kifi.  Kalk.,  p.  255),  assorts  positively  the  presence  of  five  basals.  lie  com- 
pared Cti-iioeriiiHS  with  Gli/plorrhiiis  Hall,  and  supposed  both  to  have  "  parabasalia."  Sehnltze  afterwards,  in 
his  Monograph,  p.  (Vi,  proved  from  more  perfect  specimens  that  Clcnorrinus  fj/pun  has  bntyi^wr  basals,  and  no 
infrabasals,  and  referred  that  si)ecics  to  Meloerinm.  Follman,  in  bis  article  ou  the  "  Uuterdcvonischeu 
Crinoideen,"  Verhandl.  Naturli.  Vcrein,  18S7  (private  cd.,  p.  11),  revised  the  genus  Clenocriiiui  with  four 
basals,  but  pointed  out  no  characters  by  which  it  may  be  distinguished  from  MelocriHut. 

t  28th  Kcp.  N.  Y.  State  Mus.  Nat.  Uist.  (Museum  edit.),  p.  139. 


MKI,ocRI^'II).^•:. 


295 


MelocrinuB  nobilissimus  (Hall). 
Plate  XXIII.  Fiys.  la,  2,  3. 

1850.    }[(iriacnnm  iioliilisiiimiis  —  llxLh ;  I'iik'oiil.  N   Y.,  Vol.  111.,  p.  10 J,  riiite  2,  l'ii;s.  l-l,  ami  I'liitc 

2A,  Fig.  1. 
ISSl.    Metofrinus  iiobilisaimus  —  W.  ami  Si-. ;  Kcvisiou  I'aliEocr.,  rait  II.,  p.  Mi. 

A  rather  large  species.  Dorsal  cup  higher  than  wide,  obconical,  obtusely 
pentangular  above  the  costals  owing  to  a  ilcpression  in  the  upper  portions 
of  the  interradial  spaces.  The  tubular  appendages  supporting  tlie  arms  con- 
sisting of  two  contiguous  trunks,  wliich  are  composed  dorsally  of  two  rows  of 
plates.  Plates  marked  with  obscure  radiating  ridges ;  the  suture  lines  well 
defined,  with  a  shallow  pit  at  each  angle. 

Basals  wider  than  long,  formed  into  a  small  subcjlindrioal  cup,  not  pro- 
jecting beyond  the  column.     Radials  larger  than  the  costals,  about  as  wide 
as  long.     The  second  costals  with  an  obtuse  angle  above.     Disticlials  3X  10, 
about  half  the  size  of  the  costals,  the  upper  ones  axillary  and  supporting 
upon  their  outer  sloping  faces  a  lateral  arm,  of  wliich  the  four  or  five  proxi- 
mal plates,  which  are  longer,  are  incorporated  into  the  calyx  ;  wliile  the  inner 
sloping  faces  are  followed  by  a  row  of  from  six  to  seven  palmars.    The  latter 
form  a  vertical  line  with  the  disticlials,  and  tiic  plates  of  adjoining  divisions 
are  connected  laterally,  except  the  two  proximal  ones  of  oni'li  side,  between 
which  are  interpo.sed  small  irregular  interdistichals.     The  fourth  and  fifth 
orders  of  brachials  consist  of  five  plates,  the  sixth  and  all  orders  to  tiie  niutli 
of  four,  the  succeeding  ones  of  three,  and  those  near  the  top  of  but  two 
pieces.     The  brachi  Us  are  arranged  longitudinally,  and  connected  suturally 
with  those  of  the  opposite  branch,  so  as  to  form  a  compound,  free  tubular 
appendage,  from  which  the  arms  arc  given  off  at  opposite  sides,  the  axillaries 
supporting  on  tiieir  longer  sides  the  next  order  of  brachials,  and  on  their 
shorter  ones  an  arm.     There  are  about  thirty  arms  to  each  side  of  the  ray, 
rising  to  the  same  general  height;  all  composed  from  the  second  plate  up  tif 
two  series  of  interlocking  pieces,  and  all  pinnule-bearing.     Eegular  inter- 
radial spaces  narrow  but  long;   the  first  plate  rests  within  a  deep  notch 
between  two  radials,  and  is  somewhat  larger  than  tlie  others ;  the  succeeding 
ones  are  not  arranged  in  horizontal  rows,  but  alternate  witli  one  another ; 
they  are  hexagonal,  and  the  upper  lateral  faces  of  the  one  plate  resi  against 
the  lower  lateral  faces  of  the  other,  thus  forming  two  longitudinal  rows  side 
by  side,   each  composed  of  about   twelve  plates,  which   decrease    in   size 


P 


J 


296 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


upwind.  Anal  intermdius  considerably  wider,  and  flattened  instead  of  being 
grooved  as  in  the  case  of  the  other  four ;  the  first  plate  is  the  largest,  and  is 
followed  by  tliree  pieces  in  tlie  second  row,  and  these  by  three  or  four  pieces 
in  the  succeeding  rows.  Interdistichals  four,  rather  large  and  longitudinally 
arranged ;  the  upper  one  resting  between  the  two  proxinuil  palniars.  Nothing 
is  known  of  the  ventral  disk,  nor  of  the  anus.  Column  large,  round,  com- 
posed near  the  calyx  of  moderately  long  joints  alternating  with  shorter  ones ; 
suture  lines  distinctly  waving. 

JIufizon  and  Locality.  —  Pentamerus  limestone ;  Litchfield,  Herkimer 
Co.,  N.  Y.,  and  apparently  also  found  in  the  Niagara  group  of  Western 
Tennessee. 

T^jics  in  the  American  Museum  of  Natural  History,  New  York. 

Melocrinus  paohydactylus  (Co.vrau). 
Plate  XXIII.  Figs.  4  and  5,  and  Plate  XXIV.  Figs.  4a,  b. 


1S41. 

1S59. 
1831. 


Js/rocriiii/es  paciytlae/ff!ii»  —  Conrad;  Aun.   Rep.   Pnlscont.  N.  Y.,  p.  34.    Also  Mather  1843; 

Geol.  Rep.  N.  Y.,  p.  216. 
Miiriiicriiiiis  pacliydaelylus  —  Hall  ;  Palreont.  N.  Y.  Vol.  III.,  p.  107.  I'liite  3,  Tigs.  1-4. 
Jlelocriiius  pachydaclj/lua —  W.  mid  Sp. ;  Revision  PiiliEOcr.,  Part  II.,  p.  122. 

Syii.  Actiiiocriniis  polydartyhn  BoNNY  (not  S.  A.  Miller)  ;  Sclieneetady  Reflector  of  1835. 

Sjii.  ilariucriiiiis paucidacli/lus  IIall  ;  Palrcout.  N.  Y.,  Vol.  III.,  p.  109,  Plate  3,  Fig.  5. 

Sjii.  Melocrinus  paucidacti/lus  —  W.  and  Sp. ;  Revision  Paltcoer.,  Part  II.,  p.  122. 

Smaller  than  the  preceding  species ;  dorsal  cup  shorter  and  with  convex 
sides ;  interradial  spaces  not  grooved,  although  slightly  impressed  in  the 
uppe>'  portions ;  the  radiating  ridges  upon  the  surface  much  more  conspicu- 
ous, and  ending  m  a  node  at  the  centre  of  the  plates ;  the  arms  given  off  at 
greater  intervals,  and  the  pinnules  less  closely  packed  together  than  in  that 
species. 

Basals  formed  into  a  short  spreading  cup,  of  which  the  lower  margin 
is  slightly  projecting.  Radials  and  costals  of  nearly  equal  size,  as  wide 
as  long ;  both  covered  by  a  broad,  flattened  ridge,  which  bifurcates  on  the 
second  costal  and  follows  the  distichaLs.  Narrower  ridges  pass  out  to  the 
intcrbrachials.  Distichals  3  X  10,  smaller  than  the  costals.  The  axillaries 
support  upon  the  inner  sides  of  the  ray  from  seven  to  eight  palmars,  which 
are  laterally  connected ;  at  their  outer  sides  the  proximal  arms,  of  which 
the  five  lower  plates  are  considerably  the  longest,  and  form  part  of  the  calyx. 
The  two  lower  palmars  of  each  side  are  longer  than  the  upper  ones,  and 
those  of  the  one  division  are  separated  from  those  of  the  opposite  side  by  a 


H- 


1 

j 


^1 


MELOCRINIDiE. 


297 


small  interdistichnl.  The  surface  of  these  plates  is  covered  by  radiating 
ridges  and  nodes ;  while  that  of  the  succeeding  ones  is  without  ornamenta- 
tion, and  the  plates  are  transversely  arranged.  The  brachials  of  the  fourth 
order  consist  of  six  plates,  those  of  the  succeeding  ones  of  five,  rarely  four 
(so  far  as  observed) ;  all  transversely  arranged,  and  suturally  connected  with 
their  fellows  of  opposite  sides,  forming  five  long  tubular,  arm-bearing  trunks. 
The  arms  of  this  species  are  more  slender  than  in  the  preceding  one,  and 
slightly  more  tapering,  the  pinnules  longer;  they  are  flattened  on  the  back, 
and  the  surface  is  corrugated.  Interradial  spaces  composed  of  about  twelve 
plates  arranged  in  two  longitudinal  rows,  the  plates  alternating  with  one 
another.  The  anal  interradius  and  ventral  disk  are  not  visible  in  the  speci- 
mens. 

Horizon  and  Localily. — Schoharie  Co.,  N.  \.;  Lower  Helderberg  group. 

Ti/pes  in  part  in  the  American  Museum  of  Natural  History,  New  York. 


r 


MelOCrinUS  bainbridgensis  Hall  and  Whitfield. 
Plate  XXII.  Figs.  4a,  b,  c,  and  Plate  XXIV.  Fig.  5. 

1875.    Melocrinus  (Cleiiocrinus)  bainbridgensis  —  Gcol.  Surv.  Ohio,  Palicout.,  Vul.  II.,  p.  158,  Plate  13, 

Figs.  2  and  3. 
1881.    Melocrinus  buitibrittgensii  —  W.  and  Sp. ;  Revision  PaliBoci'.,  Tart  II.,  l>.  121. 

Sjn.  Melocrinus  Clarhei  Williams;  1882,  Proceed.  .\cad.  Nat.  Sci.  Pliila.,  p.  31. 

Specimens  above  medium  size.  Dorsal  cup  as  high  as  wide,  rather  rap- 
idly spreading ;  sides  somewhat  convex ;  cross-section  pentangular.  Plates 
slightly  elevated,  beveled  at  their  margins  ;  the  middle  part  a  little  depressed, 
and  covered  with  a  system  of  confluent  granules;  the  suture  lines  grooved. 

Basals  forming  a  low  cup  with  a  sm.all  rim  around  the  lower  margin, 
which  is  notched  at  the  interbasal  sutures ;  axial  canal  pentalobate.  Radials 
and  costals  wider  than  long,  decreasing  in  size  upwards.  Distichals  3  X  10, 
those  of  the  same  ray  in  contact  laterally,  interdistichals  not  being  repre- 
sented ;  the  proximal  one  less  than  half  the  size  of  the  second  costal,  and  as 
long  as  wide ;  the  two  others  much  shorter.  The  third  plate,  which  is  axil- 
lary, supports  upon  its  inner  face  the  next  order  of  brachials,  at  the  outer 
the  proximal  arm  which  is  free  from  its  origin.  The  brachials  of  the  suc- 
ceeding orders  also  consist  of  three  pieces,  which  are  transversely  arranged, 
and  those  of  the  same  ray  are  laterally  connected,  forming  trunks  from 
which  arms  are  given  off  at  every  third  plate.  The  trunks  taper  upward,  and 
are  deeply  grooved  along  the  line  of  contact  of  the  two  branches.     Arms 

38 


J  . 


•) 


tl 


tjmiii 


II 


298 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


thin,  tliroad-like,  with  closely  packed  pinnules.  Regular  interbrachials : 
1,  2,  3,  and  others  above,  which  gradually  intermingle  with  the  interambu- 
lacrals.  The  flrst  interbrachial  of  the  anal  side  is  somewhat  the  largest,  and 
is  followed  by  three  plates  in  the  second  row,  which  form  an  arch,  and  by 
four  pieces  in  the  third  and  fourth  rows.  Ventral  disk  low,  depressed-pyra- 
midal, apparently  surmounted  by  a  subcentral  anal  tube ;  the  plates  more 
or  less  uniform,  of  about  medium  size,  and  somewhat  convex. 

Iloraon  and  Locallljj.  —  In  a  limestone  layer,  six  inches  in  thickness, 
above  the  base  of  the  Black  Slates,  Bainbridge,  Ross  Co.,  0.,  and  at  Canan- 
daigua,  N.  Y.,  in  rock  of  about  the  same  age. 

Ti/pe  in  the  Ohio  State  collection,  Columbus. 

Remarks. — Prof.  J.  M.  Clarke  of  Albany  had  the  kindness  to  send  us 
gutta-percha  casts  of  the  types  of  Melocrinua  Clarkei  Williams,  which  we 
regard  as  identical  with  M.  hatnl>rid(/emis. 


Meloorinus  gracilis  AV.  and  Sp.  (nov.  spec). 
Plate  XXII.  Fig.  5. 

A  rather  small  species,  of  the  type  of  Melocriims  (Ctcnocrimts)  stellam 
Roemer.  Dorsal  cup  obpyramidal ;  the  radials  and  costals  strongly  curved 
so  as  to  form  broad,  very  conspicuous  longitudinal  ridges  with  a  small 
tubercle  at  the  centre  of  each  plate,  tho^ie  of  the  axillaries  being  the  longest 
and  sharpest.  Interbrachial  spaces  depressed,  giving  to  the  section  across 
the  second  costals  a  sharply  pentangular,  somewhat  stelliform  outline. 

Basal  cup  low,  broadly  truncate  at  the  bottom,  its  lower  edges  slightly 
projecting  beyond  the  column ;  the  upper  angles  turned  abruptly  upwards. 
Riidials  and  costals  nearly  equal  in  size,  wider  than  long,  but  the  curvature 
makes  them  appear  to  be  longer  than  wide.  Distichals  2X10,  rounded  like 
arm  plates ;  short,  transversely  arranged,  those  of  the  same  ray  separated  by 
one  or  two  minute  interdistichals,  which  rest  within  the  bottom  of  a  shallow 
pit.  The  arm  trunks  bend  outward,  are  heavy,  and  composed  of  two  rows 
of  short  pieces.  The  arrangement  of  the  arms  cannot  be  ascertained,  as  in 
the  single  specimen  the  trunks  are  preserved  only  to  the  fourth  plates,  and 
of  the  arms  only  fragments  of  a  single  one.  Interbrachials  numerous, 
slightly  decreasing  in  size  upward ;  arranged :  1,  2,  3,  3,  etc.  They  are 
somewhat  convex  and  ornamented  with  obscure  radiating  ridges,  which  con- 
nect with  the  interambulacral  plates.    Ventral  disk  elevated,  and,  so  far  as 


MELOCRINID^E. 


299 


known,  composed  of  rather  small  pieces.  Form  and  position  of  anus  un- 
known. Colunm  round,  strong ;  the  nodal  joints  projecting,  the  intervening 
ones  knife-like. 

Horizon  and  LocaUty.  —  Hamilton  group ;  Canandaigua  Lake,  N.  Y. 
I'ype  in  the  collection  of  Prof.  J.  M.  Clarke,  now  in  the  State  Museum  at 
Albany. 

Meloorinus  Tiflfanyi  W.  and  Sr.  (nov.  spec). 
Plate  XXII.  Figs.  7a,  b. 

Calyx  pyriform ;  the  sides  nearly  straight  from  the  top  of  the  basals  to 
near  the  bases  of  the  arms ;  the  tegmen  depressed-hemispherical ;  cross- 
section,  as  seen  from  above,  obtusely  pentangular.  Surface  of  plates  orna- 
mented by  faint  ridges,  radiating  from  near  the  centre  of  the  plates  to  the 
centre  of  adjoining  ones. 

Basals  projecting  laterally,  forming  four  conspicuous,  elongate  nodes; 
the  lower  part  somewhat  excavated  for  the  reception  of  the  column.  Radials 
and  costals  gradually  decreasing  in  size  upwards,  about  as  long  as  wide ;  the 
second  costals  not  more  than  half  the  size  of  the  radials.  Of  the  distichals 
two  plates  are  preserved ;  the  lower  one  fully  one  half  smaller  than  the 
preceding  axillary ;  the  second  short,  shaped  like  an  arm  joint  and  curving 
outwards.  There  are  no  interdistichals,  all  plates  of  the  arm  trunks  being  in 
contact  laterally.  Interradial  areas  on  a  plane  with  the  radials  and  costals ; 
the  first  interbrachial  tlie  same  size  as  the  radials,  and  followed  in  the  type 
specimen  by  two  plates  at  three  of  the  sides,  but  in  the  posterior  and  right 
antero-lateral  interradius  by  three,  and  these  by  numerous  rows  of  from 
three  to  four  plates,  which  connect  with  the  disk  pieces.  Ventral  disk 
depressed-hemispherical,  the  plates  very  uniform,  rather  large,  having  the 
size  of  the  third  row  of  interbrachials.  They  sire  ornamented  like  the  plates 
of  the  dorsal  cup,  but  are  a  little  more  convex.  There  are  apparently  no 
orals.  Anus  excentric,  probably  connected  with  a  tube.  Arms  unknown ; 
column  round. 

Horizon  and  Locality.  —  Hamilton  group ;  New  Buff.alo,  lown. 

T^2^e  in  the  collection  of  Mr.  S.  A.  Tiifany  of  Davenport. 


300. 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


MelOOrinUB  Calvini  W.  and  Sr.  (nov.  spec). 
Plate  XXII.  Fly.  6. 

Similar  to  the  preceding  species,  but  the  sides  of  the  dorsal  cup  convex, 
and  the  general  form  of  the  calyx  subovoid ;  the  basals  less  projecting ;  the 
radials,  fixed  brachials  and  interbrachials  —  the  latter  to  the  third  row  — 
crowned  by  a  large,  rather  conspicuous  rounded  node  without  other  orna- 
mentation; the  upper  interbrnchial  and  interambulacrul  plates  a  little 
convex. 

Bujsals  projecting  laterally,  and  forming  four  rather  conspicuous  nodes 
around  the  columnar  attachment  which  is  a  little  projecting.  Radials  and 
costals  longer  than  wide.  The  distichals  of  the  same  ray  in  contact  laterally. 
Regular  interbrachial  spaces  large,  but  slightly  depressed  between  the  arm 
trunks;  the  plates  arianged:  1,  2,  3,  3,  the  upper  ones  insensibly  connecting 
with  the  plates  of  the  ventral  disk.  Anal  interradius  widest,  having  three 
plates  in  the  second  row.  Ventral  disk  short;  the  plates  rather  .small  and  of 
uniform  size ;  orals  apparently  unrepresented.  Anus  excentric,  probably  at 
the  end  of  a  narrow  tube. 

Horizon  and  LociiUt/j.  —  Hamilton  group ;  Johnson  Co.,  Iowa. 

Ti/pe  in  the  collection  of  Prof.  S.  Calvin  of  Iowa  City,  in  whose  honor 
this  rare  species  is  named. 

MelOOrinuS  oblongUS  W.  and  Sp.  (nov.  spec). 
Plate  XXII.  Figs.  9  and  12. 

A  rather  slender  species  of  less  th.an  medium  size.  Dorsal  cup  obconical ; 
the  sides  straight  to  the  top  of  the  second  costals,  whence  the  rays  turn  out- 
ward and  form  distinct  lobes  around  the  calyx,  which  give  to  the  section 
a  decidedly  pentalobate  outline.  Plates  convex,  a  little  nodose,  but  without 
ornamentation. 

Basals  small,  subequal,  notched  at  the  sutures;  the  lower  face  but  slightly 
truncate,  and  very  little  excavated.  Radials  and  first  costals  generally 
longer  than  wide,  especially  the  former;  the  second  costals  often  as  wide 
as  long.  Distichals  2  X  10,  the  two  upper  ones  axillary  and  separated  by 
a  small  interdistichal.  The  arm  trunks  not  preserved  in  the  specimens,  but 
as  there  are  two  distichals,  the  trunks  must  have  been  formed  of  two  rows  of 
plates.      The  first  interbrachial  as  large  as  the  first  costal;   succeeded  by 


I 


,  / 


V 


MELOCRFNIDTE. 


801 


rowa  of  2,  3,  3,  and  three  plntoH,  which  meet  the  interambuhicrals.  Anal 
interradius  a  little  wider,  with  three  plates  in  the  second  row,  and  four  in 
the  third.  Ventral  disic  low,  irregularly  convex;  the  ninbulacral  spaces 
slightly  elevated  ;  the  plates  —  orals  included  —  alnio><t  of  uniform  size. 
Anus  subcentral ;  at  the  end  of  a  tube. 

Ilorizon  and  Locality.  —  Niagara  group ;  near  Louisville,  Ky.,  and  St, 
Paul,  Ind. 

Types  in  the  collection  of  Wachsmuth  and  Springer. 

Remarks.  —  This  form  was  regarded  by  Roenier*  as  specifically  identical 
with  his  Cytocnus  Icevis,  which  comes  from  the  same  horizon  in  Tennessee, 
and  resembles  it  in  general  form ;  but  the  arm  trunks  of  that  species  are 
composed  of  single  joints,  and  it  has  a  smaller  number  of  interbrachials. 


Meloorinus  Roemeri  w.  and  Sr.  (nov.  spec). 
Plate  XXII.  Figs.  11a,  h. 

Syii.  Ci/iocriniis  hefh  —  Roemkri  1800.     Siltir.  Fnuim  West.  Tcnii.,  p.  Ifi,  Plate  4,  Figs.  2a,  h,  c. 

Syii.  Ctenoeriiim  hevis  —  Siiumaud;  1800.    Trniis.  Acad.  Sei.  St.  Louis,  p.  301, 

Sjii.  Melocriiiiia  licvis  (not  Goldf.)  —  W.  and  Sp.  (iu  part);  1881.     Revision  rnlicocr.  Part  11.,  j).  122. 

Calyx  moderately  small,  turbinate ;  dorsal  cup  about  as  wide  as  high, 
gradually  spreading  to  the  arm  bases,  which  are  formed  into  five  very  con- 
spicuous lobes,  giving  to  the  calyx,  as  seen  from  above,  a  decidedly  stellate 
outline.  Plates  without  ornamentation,  a  little  concave,  except  the  median 
line  of  the  radial  plates,  which  is  obtusely  angular.  The  radial  ai)pendages 
from  which  the  arms  are  given  off  composed  of  a  single  series  of  plates. 

Basals  rather  large,  subequai,  forming  a  shallow  cup,  which  is  slightly 
truncate  at  the  lower  end,  Radials  twice  as  largo  as  the  first  costals,  hexa- 
gonal, about  as  wide  as  long ;  their  upper  sloping  faces  a  little  larger  than 
the  corresponding  lower  ones.  Second  costals  very  small  and  curved  like 
arm  plates;  their  upper  sloping  faces  unequal,  that  toward  the  outer  side  of 
the  ray  much  the  longest,  and  supporting  a  distichal,  the  inner  one  the  first 
arm  plate.  The  trunks,  which  consist  of  a  single  series  of  plates,  give  off  the 
arms  at  intervals  from  alternate  sides,  not  from  opposite  plates  as  in  species 
with  a  double  series.  Interbrachial  spaces  wide,  the  first  plate  large,  succeeded 
by  two  rows  of  two  and  three  plates  respectively,  which  are  followed  by  di.sk 
plates.  The  two  outer  plates  of  the  upper  row  curve  outward  and  form  the 
sides  of  the  lobes.  At  the  anal  side  the  first  plate  is  larger,  and  foUoweti  by 
»  Silur.  Fauna  West.  Tennessee,  1860,  p.  48. 


302 


TIIK  CUINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


i     *' 


three  plates  in  the  second  row,  and  four  in  the  tliird.  Ventral  disk  depressed, 
pentagonal ;  the  anibulacral  regions  slightly  raised  above  the  general  level ; 
the  plates  without  ornamentation,  almost  flat,  and  the  sutures  difficult  to  see. 

The  disk  ambulacra  are  completely  subtegniinal ;  the  orals  apparently 
unrepresented,  and  the  anus  is  at  the  end  of  a  large  tube,  which  bends 
toward  the  posterior  side. 

Ilurhon  and  Londilij.  —  Niagara  group ;  associated  with  Aistraospomjia 
meniscus.     Decatur  Co.,  Tenn. 

T//pe  in  the  collection  of  Wachsmiith  and  Springer. 

Itemurkn. — Roenier  descril)ed  this  species  as  Cytocrinus  Iccvis,  mnkmg  it 
the  type  of  a  new  genus.  lie  supposed  it  hud  three  basals,  and  he  did  not 
understand  its  arm  structure,  which  is  evidently  that  of  Mclocrinus.  We 
refer  the  species  to  the  latter  genus,  but  are  compelled  to  change  the  specific 
name,  as  Goldfiiss  in  1826  described  a  Mdocrimis  Iwvis  from  the  Eifel,  and 
propose  for  it  Mclocrinus  Jiocmcri  Roemer  originally  included  in  his  species 
two  forms,  the  typical  one  from  the  Niagara  group  of  Western  Tennessee, 
and  another  from  the  same  horizon  of  near  Louisville.  The  latter  has  been 
described  by  us  as  Mchcrinus  ohlonrjus.  The  two  species  resemble  each  otlier 
in  form,  but  3[.  uhlongus  is  considerably  larger,  the  calyx  contains  many  more 
plates,  and  the  radial  appendages  are  composed  of  two  rows  of  brachials  in 
place  of  one. 

Melocrinus  oboonious  Hall. 
Plate  XXII.  Figs.  10a,  b,  c. 

1863.     X'l'hrriiiiis  ohnnicus  —  IIall|  Tmiis.  Alb.  Tnst.,  p.  ZOfi. 

1875.     Melucriiiim  obroiiinia  —  WKLh ;  2Slli  Ucp.  N.  Y.  Slate  M  us.  Nut.  Hist.,  p.  138,  Tlnte  14,  Figs.  11-14. 

1S81.     Mtlucriniis  obcomfiia—\\\u.\  IKli  Ann.  Hep.  Geol.  Ind.  by  Collet,  p.  269,  Plate  13,  Fgs.  11-14. 

18S1.     Mariarriims  obconieua  —  W.  nud  Sp. ;  Uevision  I'alicocr.,  Part  II.,  p.  116. 

» 

Of  medium  size.  Calyx  obconical,  about  as  wide  as  high;  gradually 
expanding  from  the  top  of  the  basals  to  the  bases  of  the  free  appendages, 
where  it  is  distinctly  lobed.  Plates  covered  by  numerous  radiating  ridges, 
which  pass  out  from  the  middle  of  the  plates  to  the  sides  and  angles,  meet- 
ing those  of  adjoining  plates;  the  ridges  passing  up  and  down  the  radial 
plates  wider  and  somewhat  higher.  Besides  these  ridges  the  whole  surface 
of  the  plates  —  that  of  the  ridges  included  —  is  finely  corrugated,  which  adds 
greatly  to  the  beauty  of  the  species. 

Basals  projecting,  forming  a  short,  indistinctly  quadrangular,  almost  cylin- 
drical cup.     Radials  and  costals  of  about  equal  size,  and  all  nearly  as  long 


i 


MELOCUIMDvE. 


303 


as  wide.  Distlchnls  two,  the  two  divisions  separated  by  one  or  two  iiiter- 
distichals  Palinars  apparently  not  united  laterally,  and  there  may  have 
been  two  appendages  to  each  ray  Interradial  spaces  depressed  in  the  upper 
portions;  arranged:  1,  2,  "  with  numerous  plates  above,  which  connect 
with  others  in  the  disk.  A..  J  area  somewhat  the  widest,  and  with  three 
plates  in  the  second  row.  Ventral  disk  almost  Hat ;  composed  of  very  uni- 
form, slightly  convex  pieces.     Anus  excentric,  probably  without  a  tube. 

Horizon  and  Locality.  —  Niiigara  group;  Waldron  and  Ilartsville,  Ind. 

Tifpe  in  the  American  Museum  of  Natural  History,  New  York. 

MeloorinuB  parvus  AV.  and  Sp. 
riatc  XXII.  FUj.  8. 

1S92.     W.  mill  Sp.  ;  Aincr.  Geologist  (September  number),  Vol.  X.,  p.  141. 

A  small  and  very  slender  species  of  the  type  of  3Iclocriinis  liocmcri,  hav- 
ing like  that  species  five  uniserial  radial  appendages.  Dorsal  cup  obpyr- 
amidal,  the  interradial  spaces  deeply  depressed,  and  the  cross-section  at  the 
top  of  the  costals  distinctly  pentalobate.  The  plates  a  little  convex  and 
covered  with  obscure  ridges. 

Basal  cup  almost  cylindrical,  its  upper  end  slightly  the  widest,  the  lower 
face  completely  covered  by  the  column ;  the  plates  as  high  as  the  radials, 
and  the  interba.sal  and  basi-radial  sutures  distinctly  grooved.  Endials  a  little 
longer  than  wide.  First  costals  of  the  same  proportions  as  the  radials. 
Second  costals  smaller,  proportionally  shorter,  and  irregularly  axillary ;  one 
of  their  upper  faces  short  and  giving  off  an  arm,  the  other  a  row  of  distichnls, 
which  are  followed  by  higher  orders  of  brachials,  and  arms  given  oil  at  inter- 
vals from  opposite  sides.  Interbrnchials  three  at  the  regular  sides,  and  four 
at  the  anal  side,  the  latter  having  three  plates  in  the  second  row  ogainst  two 
at  the  other  sides.  Ventral  disk  convex,  the  interambulacral  spaces  a  little 
depressed ;  composed  of  moderately  large,  slightly  convex  plates.  Arms 
excentric. 

Horizon  and  Loealif//.  —  Niagara  group ;  St.  Paul,  Ind. 

Type  in  the  collection  of  Wach«muth  and  Springer. 

Remarks.  —  This  species  differs  from  M.  lioemeri  in  the  narrower  and 
less  spreading  base,  in  the  proportions  of  the  radials  r.nJ  costals,  and  in  the 
convexity  of  the  plates. 


P 


304 


THE  CKLNOIDKA  CAMEHATA  OF  NORTH  AMKKICA. 


MeloorinuB  sequalis  H.  A.  ^[h.lkk. 

isijj.     Adv.  Shi'uU  IMlh  U('|i.  (irol,  »urv.  lii(liiiiiii,  p.  IS,  I'luto  6,  Figs.  11  and  12. 

A  iiiotlenitely  Hiiiall  species.  DoihiiI  cup  obpyrainidiil,  decideilly  peut- 
iingiiliir  lit  tlio  una  bases,  dooply  sunken  inteniidially.  All  plates  of  tlio 
calyx  heavy  and  tiiinid  ;  those  of  the  dorsal  cup  covered  with  short  ridj^es 
at  their  margins,  one  to  each  side,  the  median  portions  of  the  plates 
stnootli.  Suture  lines  well  marked.  The  radial  appendages  directed  almost 
horizontally. 

IJasals  nearly  equal,  longer  than  wide,  the  sides  very  little  expanding. 
Radials  as  long  as  the  basals,  a  little  wider  than  long.  First  costals  hexa- 
gonal, almost  as  large  as  the  radials  ;  the  S(  cond  smaller  and  irregularly 
axillary,  giving  off  at  the  shorter  side  an  arndet,  and  at  the  longer  the  next 
order  of  brachials.  Rays  free  above  the  costals,  and  evidently  composed  of 
a  single  row  of  plates,  with  arms  given  off  at  nlternato  sides,  Interradial 
areas  probably  alike;  the  first  interbrachial  nearly  as  large  as  the  adjoining 
costal,  followed  by  two  and  three  smaller  plates,  of  which  the  latter  occupy 
the  arm  regions.  Plates  of  the  tegmen  very  large,  composed  of  onl^  two 
rings,  the  upper  supporting  a  massive  anal  tube,  composed  of  tumid  or  nodose 
plates. 

JIurizon  and  Locdihj.  —  Niagara  group,  St.  Paul,  Ind. 

Remarks.  —  This  species  resembles  M.  iwrvus  in  liaving  simple  free  rays, 
but  differs  from  it  distinctly  in  the  form  of  the  calyx,  the  greater  convexity 
of  the  plates,  in  liaving  a  much  stronger  anal  tube,  and  the  rays  directed 
horizontally. 

Our  description  was  made  after  Miller,  and  from  fragmentary  specimens  in 
our  collection. 

II.   DOLATOCRTNITES. 

SYMMETRY   OP   THE  DORSAL   CUP   UNDISTURBED    BY   ANAL   PLATES. 

TECHNOCRINUS  Hall. 

1S.J0.  1I.4LL ;  Palicnnt.  New  York,  Vol.  III.,  p.  139. 

1870.  Zittel;  llirndb.  dor  Pidicnnt,,  Vol.  I.,  p.  372. 

18S1.  W.  mid  Sp.  ;  Revision  Palteocr.,  Part  II.,  p.  116  (Proceed.  Acad.  Nat.  Sol.  Pliiln.,  p.  290). 

1889.  S   A.  Mii.r.Eii ;  N.  Amor.  Gcol.  mid  Pnlicoiit.,  p.  2S0. 

Calyx  large;  symmetry  perfectly  pentahedral  up  to  the  arm  base.", 
except  a  slight  irregularity  in  the  basal  cup.     Basals  four,  somewhat  un- 


OCRIND^i;. 


r* 


uqunl,  arranged  ns  in  M  'ncrimiH,  1  iir  of  tliP  rndiiilH  hep(|^o»«I.  iho 
anterior  one  liexiigoiial.  Cu-.Uls  two  ;  he  llrni  h  vngonal,  the  secoud  gpii' 
emily  pentagonal.  Disticlmls  1x10,  all  Axillary.  The  finr  Jilninr,  u..<l 
Honietiujen  the  Hecoiul,  takes  part  in  tlie  calyx;  'tie  »uccee<!  .g  ones  being 
arm  [dates.  Arms  long,  simple,  straight,  bisein,  i ;  fringed  by  good-sized 
pinnules,  which  are  in  contact.  Interbraehials  three  or  foiir,  but  no  inter- 
disticlials.  Structure  of  ventral  disk  and  anus  unknown.  Column  round ; 
tapering. 

Dls/r!hiilion.  —  The  genus  is  known  only  from  the  Oriskany  Sandstone  of 
Maryland. 

Tijjjc  of  the  genus :   Technocrinits  uplmilosva  Hall. 

JReinarks.  —  Tcchitncrlnm  differs  from  Marlarriwrn  and  Mclocrinns  in  the 
perfect  pentamerous  symmetry  of  its  dorsal  cup,  and  from  the  former  in  hav- 
ing one  instead  of  three  to  four  distichala,  no  interdistichals,  and  the  arms 
arranged  in  an  almost  continuous  series  around  the  calyx  ;  while  the  orms  of 
Jfiiruwriniis  are  arraTiged  in  groups.  It  differs  from  Melncrimis  in  having  sim- 
j)le  arms  given  off  directly  from  the  calyx,  and  not  from  its  tubular  extensions. 

Technomnus  striutus  and  T.  sculptus  Hall,  were  described  from  detached 
basal  plates. 

Teohnoorinus  splnulosus  Hall. 

Plate  XXIL  Fig.  3. 

1859.    Hall;  Palicont.  New  York,  Vol.  III.,  p.  140,  Plate  85,  Figs.  1-lS. 
1881.    W.  and  8p.  i  Revisiou  PaliEOcr.,  Part  II.,  p.  117. 

Calyx  subglobose,  the  arm  bases  slightly  contracting.  Plates  of  the 
dorsal  cup  marked  by  a,  central  spine  or  node,  surrounded  by  smaller 
nodes,  which  vary  in  number  among  the  plates.  From  the  nodes  two  to 
four  parallel  ridges  pass  out  to  the  sides,  and  these  are  continued  upon 
adjoining  plates.  Near  the  arm  bases  the  ri(^ges  gradually  disappear,  and 
the  plates  are  marked  only  by  a  central  spine. 

Basals  four,  of  medium  size,  forming  a  shallow  basin  with  five  sets  of 
four  ridges,  each  set  communicating  with  those  upon  the  radials.  Eadials 
and  costals  nearly  as  wide  as  long,  decreasing  in  size  upwards ;  the  necond 
costal  but  half  the  size  of  the  first.  Distichals  one  to  each  side  of  the  cos- 
tal axillaries.  The  first  palmar  enclosed  in  the  calyx.  Arms  twenty,  stout, 
rounded  ;  composed  at  their  bases  of  cuneate  pieces,  which  interlock  farther 
up,  and   gradually  become  biserial.    Interbraehials  apparently   four.     All 

39 


•^ 


M 


SU6 


TIIK  f  HINOIUKA   CAMKUATA  OF   NOHIU   AMKUIt'A. 


other  parts  of  tliu  calyx  unknown.     Culomn  Mliglitly  pi>ntMH;onaI,  cuch  altor- 
natu  joint  provided  with  a  node  or  sliort  Hpinu  at  tlie  margin. 

lliirixna  ami  Luculilij.  —  Oriwiiany  Hand,stono,  Cuniljorland,  Md. 

Tiji)e  in  tlio  Aniurican  MuHuuni  of  Natural  Ilitttory,  Nuw  Vurk. 

TeohnooriQui  Andrewti  IIali.. 
I'luieXXJV.Fig.3. 

1S50.     II*ll ;  I'liliri.iit,  New  York,  Vol.  Ill,,  p   IH,  Pluto  86,  Figl.  1-4. 
18SI.     W.  uiiil  Si'. ;  llcvisioii  I'ulndir ,  I'iiil  11.,  p.  117. 

A  rather  large  Bpecies.  Calyx  to  tho  nrin  bosoH  hemispherical  ;  platen 
moderately  convex,  surrounded  by  Hcts  of  short  marginal  ridges  paxsing  in- 
ward, three  to  four  to  each  side  of  tho  plato,  and  by  small  pits  ali>ng  tho 
sutures;  tho  centre  of  the  plates  perfectly  smooth.  Ilasals  wider  than  high. 
Radials  large,  about  as  long  as  wide.  First  costuls  of  the  form  of  the  radi- 
nis,  but  considerably  smaller ;  the  second  still  smaller,  narrower  as  well  as 
shorter.  Dlstiehals  one,  axillary ;  supporting  in  tho  calyx  two  rather  largo 
palnuus,  followed  by  several  cuncate,  interlocking  free  plates,  and  thef<e  by 
two  rows  of  subquadrangular  pieces,  united  by  a  sharply  zig/ag  suture. 
Arms  four  to  the  ray,  strong,  flat,  and  of  almost  uniform  width  throughout. 
Pinnules  contiguous.  Interbrachials  four  or  five:  1,  2,1,  1,  all  compara- 
tively large.  Column  round,  large,  tapering ;  the  joints  rather  long  and 
slightly  rounded  exteriorly. 

Horizon  and  LocalUij.  —  Oriskany  Sandstone,  Cumberland,  Md. 

Type  in  the  American  Museum  of  Natural  History,  New  York.  The 
species  is  described  and  figured  from  a  cast  made  from  tho  natural  mould  in 
tho  rock. 

ALLOCRINUS  W.  and  Sp. 

1880.    W.  niul  Sp.  ;  Genl.  Rep.  Illinois,  Vol.  VIII.,  p.  200. 

Calyx  small ;  the  arms  stout ;  symmetry  of  dorsal  cup  equilateral. 
Basals  three,  small,  unequal  —  the  left  antero-lateral  plate  one  half  the 
smaller  —  forming  a  di.sk,  which  is  almost  completely  covered  by  the  col- 
umn. Eadiala  large,  much  wider  than  the  costals.  Coatals  two,  rounded 
like  arm  plates.  Arms  uniserial,  strong,  simple  ;  two  to  the  ray,  being 
free  from  the  second  or  third  distichal.  Interradial  spaces  composed  of 
two  or  three  plates,  of  which  the  first  is  much  the  largest.  Column 
small,  round ;   axial  canal  narrow,  pentangular. 


■ 


Mi:i<(M  UINII)-K. 


n(»7 


Dlstrihulinn,  —  Alhrrinux  in  rcHtricteil  to  Atiiorifu.  Tt  luildiii^'H  to  ii  litllo 
gronp  of  Crino'ulH  \\\\\vt\\  in  hpiiriiigly  ri-pre-untt'il  in  tliin  coiiiitry,  lint  of  wliicli 
ML'vi'riil  gt'iicni  with  a  iiimilK-r  of  Hpi'cioM  art'  known  to  liavo  oxiwtftl  ilnriiij,' 
tilt'  Uiiper  Silurian  puriod  in  Swi-den  and  Kngland. 

Itnntirkx.  —  TliiM  goiuiH  IniM  clone  alliniticH  witli  Piitt/lwirimit  and  Puldfo- 
I'lliniM.  It  dilTurH,  liowcviT,  fnun  both  of  tlicm  in  tho  form  and  t<i'/.c  of  the 
variouH  calyx  platon,  and  in  having  iiniHcrial  arinH.  It  idno  n|)proachuM  Clh- 
trurrliuis,  but  thin  ban  a  largo  and  [icrA'ctly  ancdiyloHod  banal  dink. 


AlloOlinUB  typUl   W.  nnd  Bp. 

PlakXXIV.FujH.  7ii,h. 

18sn.    W.  nml  8p.  ;  Ocol.  Rqi.  IlliiioK  Vol.  VIII.,  p.  207,  I'lntc  XIV.,  FiR.  7. 

Below  niedinm  mzo.  Calyx  depressed,  proportionally  small,  sharply 
pentangular  in  outline,  tho  arm  bases  projecting,  tho  arms  massivo  and 
proportionally  stoutor  than  those  of  any  otiior  Crinoid ;  the  platos  with- 
out ornamentation.  Rasals  snuill,  forming  a  llattcned  disk,  which  is  almost 
covered  by  the  column  ;  interbasal  and  l)a!<i-radial  sutures  indistinct.  Hadials 
large,  abruptly  curved,  tho  lower  portions  forming  the  rim  of  an  inverted 
shallow  basin,  tho  upper  half  bent  abruptly  upward  nnd  forming  together 
with  the  plates  above  a  shallow,  spreading  cup  with  straight  sides.  Costals 
nnd  fixed  distichals  short,  curvvnl  like  arm  plates,  producing  upon  the  sur- 
face of  the  calyx  strong,  roi  nded  ridges,  which  insensibly  pass  into  the  free 
arms.  Arms  ten,  stout,  uni  rial,  free  above  tho  second  plate;  compo.sed  of 
transverse  joints  with  parallel  upper  and  lower  faces.  The  arms  much  wider 
midway  than  at  either  end,  tapering  considerably  and  uniformly  toward  tho 
tips,  but  almost  a.s  much  toward  the  calyx.  Tnterradial  spaces  deeply  de- 
])ressed,  composed  of  two  plates  vertically  arrangei],  of  which  the  first  is  tho 
Inrgor  and  nodose,  and  extends  to  the  top  of  the  costals ;  while  the  other  is 
on  a  level  with  the  fixed  brachials,  and  forms,  to  some  extent,  a  part  of  tho 
ventral  surface.  Nothing  is  known  of  tho  anal  aperture  and  tho  structure 
of  tho  ventral  disk.     Colunm  round,  small ;  axial  canal  pcntnngulnr. 

Iliirixon  and  Localiti/.  —  Ningara  group  ;  Wayne  and  Decatur  Cos.,  Tenn. 

Ti/2Ks  in  tho  Worthen  collection,  Springfield,  nnd  that  of  Wachsmuth  and 
Springer. 


Fjk 


^^SH^I^ 


^-"^ 


308 


THE  CRINOIDEA  CAMERATA  OF  NORTH   AMERICA. 


l. 


Alloorinus  Benedioti  s.  A.  Milleu. 

rUitc  XXIV.  Figs.  Sa,  h. 

1891.    S.  A.  Miller;  Adv.  Sheets  Hlli  Itip.  Geiil.  Surv.  ludiium,  p.  37,  Plate  7,  Fig.  1. 

Closely  resembling  the  preceding  specie.^,  but  the  dorsal  cup  n  little 
smaller  and  less  sharply  angular,  the  plates  generally  more  convex,  and 
the  arms  not  quite  so  stout.  Dor.sal  cup  bowl-shaped,  a  third  wider  than 
high,  the  lower  end  distinctly  truncate,  the  sides  convex,  the  plates  elevated 
and  more  or  less  nodose. 

Basals  forming  an  equilateral  pentagonal  disk,  which  has  twice  the  diam- 
eter of  the  coUnnn,  and  occupies  the  bottom  of  a  shallow  concavity  ;  inter- 
basal  sutures  indistinct.  Kadials  large,  curving  gradually  upwards,  their 
upper  ends  at  right  angles  to  the  lower.  Both  costals  together  of  about 
the  size  of  the  radials,  wider  than  long,  the  sides  decidedly  beveled  and 
forming  a  deep  groove  toward  the  interbrachials.  First  costals  quadrangu- 
lar, the  second  pentangular.  Distichals  one  in  the  calyx,  the  others  free. 
Arms  ten,  .so  far  as  observed,  moderately  heavy  ;  their  plates  quadrangular. 
Interbrachials  one,  very  large,  elongate,  and  highly  convex  in  the  middle, 
beveled  around  the  margins.     Structure  of  ventral  disk  unknown. 

Horizon  and  Locality.  —  Niagara  group ;  St.  Paul,  Ind. 


4. 


I  i 


CENTROCRINUS  W.  and  Sp. 

ISSl.    TV.  nud  Sp.  ;  Revision  Pakocr ,  Part  II.,  p.  104  (Proceed.  Aead.  Nat.  Sci.  Pliila.,  p.  278). 
Syu.  AcHiiocriiius  (in  part)  Lyon  ;  1809,  Trans.  Ainer.  I'liilos.  Soc,  p.  453. 

Dorsal  cup  elongate,  plates  smooth.  Ba.sals  represented  by  a  large 
pentagonal  disk,  showing  no  traces  of  suture  lines.  Radials  unusually 
large,  followed  by  two  costals,  which  are  proportionally  very  smtill.  Dis- 
tichals still  smaller,  taking  the  form  of  arm  plates.  Arm  openings  large, 
directed  outward.  First  interbrachial  plates  large,  followed  by  two  smaller 
pieces.      All  other  parts  of  the  calyx  unknown.     Column  very  small. 

Distrihution.  —  Represented,  .so  far  as  known,  by  a  single  species  from 
the  Hamilton  group  of  America.  Ccntrocrimis  tennesseensis  Worthen,  from 
the  Niagara  group  of  Western  Tennessee  (Geol.  Rep.  Illinois,  Vol.  YIIL,  p. 
95,  Plate  14,  Fig.  1),  has  infrabasals,  and  is  a  totally  different  thing. 

Memarks.  —  The  name    Ccntrocrimis  was  previou.sly  proposed  by  the 


MELOCRINIDiE. 


309 


Austins,*  who  recommended  its  application  for  certain  species  of  riutjcniius 
•with  "  central  vaivate  unobstrusive  mouths,  or  mouths  capable  of  beinjj 
withdrawn  into  the  visceral  cup."  Even  substituting  "anal  opening"  lor 
mouth,  there  is  no  Platycrinoid  to  which  the  above  delinition  is  applicable ; 
besides  the  name  has  never  been  accepted  by  any  writer,  nor  was  it  applied 
to  any  particular  species  by  Austin  himself.  Cmtrocrinus,  as  here  delinod, 
is  allied  to  the  Platycrinidoo  in  its  anchylosed  large  basal  disk  and  the  small 
size  of  its  costals,  but  differs  essentially  in  having  two  rows  of  interbrachials 
within  the  limits  of  the  dorsal  cup.  Lyon's  figures  show  interbasal  sutures, 
but  they  cannot  be  seen  in  his  specimens. 

Centrocrinus  pentaspinus  (Lvo.\). 
Plate  XXV,  Figs.  10a,  b,  c. 

1869.     Jc/inomimsjienlaspiiiiis  —  hms ;  Trans.  Amcr.  Pliilos.  Soc,  Vol.  XIII.,  p.  4.58,  Plate  2fi,  Figs,  il 

and  (//. 
18S1.     Centrocrinm  pentaspinus  — Vf.  und  Sr.j  Revision  Pnteocr.,  Part  II.,  ]..  101  (Proceed.  Acad.  Nat. 

Sci.  Philn.,  p.  279;. 
Syn.  Jclinofrinu.1  midlkornus  Lyon  ;  Trans.  Amor.  Pliilos.  Soc,  Vol.  XIII.,  ]..  4.55,  Plate  20,  Tis. 

e;  and  Ccnlrocrinus  mulliconius  —  W.  and  Sp.  (Revision,  Part  II.,  p-  lOu). 

Dorsal  cup  as  wide  as  high,  subcylindrical,  flat  below,  the  sides  nt  right 
ancles  to  the  bottom.  Plates  without  ornamentation,  but  the  radial.^,  and 
sometimes  the  first  interbrachials  and  first  costals,  armed  with  a  sharp  spine, 
■while  the  other  plates  are  merely  convex. 

Basal  disk  very  large,  forming  a  regular  pentagon,  whose  surface  is 
covered  by  a  sort  of  rounded  collar,  extending  over  the  greater  part  of  the 
surface,  leaving  only  the  angles  free.  Eadials  almost  twice  as  laif-o  as  the 
two  costals  together,  the  upper  face  much  narrower  than  the  lower.  First 
costals  quadrangular,  half  the  width  of  the  radials,  and  less  than  half  their 
length;  the  second  costals  shorter  than  the  first,  pentagonal,  with  obtn.^e 
upper  angle.  Distichals  two,  short,  curved  like  arm  plates;  the  npper  ones 
excavated  to  form  the  arm  openings,  which  are  large  and  arranged  in  groups 
with  wide  interspaces.  Interbrachials  four;  the  first  plate  large,  hexagonal, 
rising  to  the  top  of  the  first  costals,  the  lower  angle  deeply  Avedgcd  in  be- 
tween the  radials;  the  two  of  the  second  range  are  followed  by  a  small  piece, 
resting  between  the  arm  bases.  Ventral  disk,  arms  and  anus  unknown. 
Column  small ;  axial  canal  apparently  circular. 

•  Thomas  Austin,  and  TLomas  Austin,  juu.,  1843,  Monogr.  Rec.  and  Foss.  Crin.,  p.  G. 


I 


1 


310 


THE   CRINOIDEA  CA^IKRATA   OF   NORTH  AMERICA, 


Iluriziiii  and  LucaUti/.  —  Upper  Hclderbcrg  group ;  Falls  of  the  Ohio, 
near  Loui.sville,  Ky. 

I'iipc  in  the  L}  on  collection  at  Jeffersonville,  Ind. 

Remarks. —  Actinocrinus  multicornus  Lyon  is  undoubtedly  a  mere  varia- 
tion of  this  species.  The  addition  of  small  spinous  extensions  upon  the  first 
costals  and  first  interbrachials  is  not  a  sufficient  reason  for  specific  distinction. 

DOLATOCRINUS  Iaon. 

1Sj7.     Lvon;  GpoI.  Rep.  Kentucky,  Vol.  III.,  p.  482. 
1877.    S.  A.  Mii.LKR;  Cat.  Amer.  Piiltcoz.  Foss.,  p.  77. 

1881.     W.  1111(1  Sp.  ;  Revision  Pnlicoer.,  Part  II.,  p.  124  (Proceed.  Acad.  Nat.  Sol.  Pliila.,  p.  208). 
Syn.  OcffiormM  — Hall;  1862,  15lh  Hep.  N.  Y.  State  Cab.  Nat.  Hist.,  p.  137. 

Calyx  depressed.  Dorsal  cup  flattened  below,  sometimes  to  the  full 
height  of  the  costid-i ;  the  plates  generally  ornamented  with  radiating 
ridges  and  nodes.  Ventral  disk  but  slightly  elevated,  surmounted  by  a 
large,  alino.st  central  tube ;  the  interambulacral  spaces  depressed.  Basnls 
anchylosed,  the  lines  of  union  obliterated.  Eadials  large  and  hexagonal. 
Costals  two ;  the  first  quadrangular,  with  convex  upper  and  lower  faces, 
narrower  than  either  radials  or  second  costals,  and  wider  than  long;  the 
upper  one  pentangular.  Distichals  two  to  four  in  species  with  only  two 
primary  arms ;  but  when  there  are  additional  bifurcations  in  the  calyx  there 
is  but  one.  Ambulacra!  openings  large,  arranged  in  groups,  with  wide 
interspaces,  and  directed  upwards.  Arms  biserial,  generally  bifurcating. 
Interbrachials  rather  numerous,  there  being  generally  three  ranges.  The  two 
proximal  rows  consist  of  a  single  plate  each,  of  which  the  first  is  the  largest 
plate  of  the  calyx,  rising  to  the  top  of  the  lir.st  distichals;  the  upper  row 
connecting  insensibly  with  the  interambulacral  plates.  The  latter  plates 
consist  in  most  of  the  species  of  a  single  row  of  from  five  to  seven  rather 
large  cuneate  pieces  —  the  smaller  end  directed  downward  —  which,  except 
the  three  middle  ones,  are  not  in  contact  laterally  throughout  their  full 
length,  their  lower  ends  being  slightly  excavated,  so  as  to  leave  narrow  slit- 
like openings  between  the  plates,  two  to  three  to  each  side  of  the  interradius, 
or  four  to  six  to  the  whole  area.  Some  species  have  two  rows  of  interambu- 
lacriil  plates  instead  of  one,  four  to  six  smaller  ones  being  placed  beneath  the 
others,  and  the  upper  margins  of  these  plates  are  slightly  pierced  by  the 
lower  ends  of  the  slits.  Above  the  interdistichal  areas,  there  are  rarely  more 
than  two  slits,  and  not  exceeding  four.     In  the  dorsal  cup,  the  arrangement 


MELOCRINID^. 


311 


of  the  interrndinl  plates  is  invariably  the  same  at  all  sides,  but  at  the  anal 
side  the  ventral  disk  has  a  few  additional  pieces,  and  the  plates  pierced  by 
tlie  slits  are  shorter.  The  disk  contains  large  orals,  pushed  anteriorly  by 
the  stout,  almost  central  anal  tube,  and  it  has  well  defined  radial  dome 
plates  of  a  first  and  second  order.  Ambulacra  subtegminal.  Column  large, 
round ;  the  sides  covered  in  some  of  the  species  by  large  angular  processes 
or  ribs ;  axial  canal  very  large  and  pentalobate. 

Z>(s^/-i6M;ion.  — Restricted  to  the  Upper  Helderberg  and  Hamilton  groups 
of  America. 

Ttii^e  of  the  genus.  —  Dolatocrinns  laciis  Lyon. 

Remarks.  —  The  complete  anchylosis  of  the  basals,  the  large  size  of  the 
first  interbrachial  and  its  being  followed  by  a  single  plate,  the  large  anal 
tube,  and  the  slit-like  openings  at  the  sides  of  the  arms,  together  with  the 
perfect  symmetry  of  the  dorsal  cup,  form  excellent  characters  of  this  genus. 

Lyon  described  the  base  as  composed  of  live  pieces,  while  Hall  mentions 
three  basals,  but  the  fact  is  that  the  sutures  are  not  visible  externally  in  the 
specimens.  Mr.  Victor  Lyon,  however,  sent  us  a  specimen  in  which  the 
presence  of  three  plates  is  indicated  at  the  inner  floor,  while  no  suture 
lines  appear  exteriorly. 

The  slit-like  openings  have  not  been  noticed  before.  We  regard  them  as 
analogous  to  the  respiratory  pores  of  Batocrinus,  from  which,  however,  they 
differ  in  number,  form  and  arrangement. 

Hall,  in  1862,  described  several  species  of  the  type  of  Dolatocrimts  under 
Cacabocrimts,  a  catalogue  name  of  Troost,  and  among  them  Cacahocriims 
Troostl  and  C.  lamellosus,  of  which  we  have  been  unable  to  get  authentic 
specimens.     The  descriptions  are  too  general  for  specific  identification. 


1S37. 
18S1. 


Dolatoorinus  lacus  Lyon. 
Flate  XXVL  Figs.  Ga-c. 

Lyon;  Geol.  Rep.  Kentucky,  Vol. .III.,  p.  48^.,  Plate  4,  Figs.  2,  2(r-c. 
W.  and  Sp.  ;  Revision  Pnltrocr.,  Part  IL,  p.  126. 


Calyx  depressed  hemispheric,  flattened  below,  somewhat  tumid  around 
the  summit.  Dorsal  cup  more  than  once  and  a  half  as  wide  as  high ;  the 
basals  and  the  lower  half  of  the  radials  deeply  incurved,  and  formed  into  an 
inverted  funnel-shaped  concavity,  which  is  wider  than  the  column,  the  latter 
touching  only  the  bottom  part.     The  upper  half  of  the  radials,  and  nearly 


V,    '"^ 


S12 


THE  CRINOIDEA   CAMERATA  OF  NORTH  AMERICA. 


.ar.'/..vj 


the  whole  of  the  first  costals,  spread  out  horizontally;  while  the  second 
costals  and  disticlials  turn  straight  upward.  The  ornamentation  of  the  dor.-al 
cup  con8i.sls  of  two  or  three  rows  of  parallel  ridges,  which  pass  out  from  the 
middle  of  the  plates  —  with  or  without  interruption  —  to  adjoining  plates, 
so  as  to  form  numerous  concentric  triangles.  A  more  conspicuous  ridge 
passes  up  and  down  the  rays.  Another,  equally  prominent,  connects  the 
radials  laterally,  and  forms  a  pentagon  around  the  basal  concavity.  The 
radials,  first  co.stals  and  first  interbrachials  are  each  surmounted  by  a  promi- 
nent node,  while  the  plates  of  the  legmen  are  covered  with  small,  granular 
prominences. 

Basals  small,  almost  completely  concealed  by  the  column  ;  forming  a 
conspicuous  cone  at  the  inner  floor  of  the  calyx.  Radials  larger  than  first 
and  second  costals  together,  their  greatest  width  equal  to  their  length ; 
their  upper  lateral  faces  shorter  than  the  lower.  First  costals  once  and 
a  half  as  wide  as  long,  the  upper  and  lower  faces  somewhat  convex.  Second 
costals  a  little  longer  and  wider  than  the  first.  Distichals  2  X  10  in  the 
calyx ;  the  lower  one  almost  as  large  as  the  preceding  axillary ;  the  others 
small,  and  supporting  the  arms  of  which  there  are  two  to  the  ray.  Arm 
bases  projecting  ;  the  ambulacrsil  openings  large.  First  interbrachials  as 
large  as  the  radiiils  and  first  costals  together;  they  rise  to  the  height  of  the 
first  distichals,  and  are  followed  by  a  single  much  smaller  plate  in  the  second 
row,  and  three  still  smaller  ones  above,  which  support  three  or  four  plates 
in  the  disk.  Orals  and  radial  dome  plates  well  defined,  larger  than  the  inter- 
ambulacrals.  Anal  tube  almost  central.  Column  round ;  the  axial  canal 
large  and  pentalobate. 

Horizon  and  Locality.  —  Hamilton  group  ;  in  the  limestone  bed  above  the 
Black  Slate  ;  Louisville,  Ky. 

Type  in  tht  Lyon  collection  at  Jeflersonville,  Ind. 

Dolatoorinus  Marshi  Lyon. 
Plate  XXVI.  Figs,  la,  b,  c,  d. 

18P.9.    Ltos  j  Trniis.  Amcr.  Philos.  Soc,  Vol.  XITI.,  p.  401,  Plate  27,  Figs.  «,»!,»  2. 
1S81.    W.  nnd  Sp. ;  ncvision  Pnloeocr.,  Part  II.,  p.  126. 

Calyx  of  medium  size,  wider  than  high.  Dorsal  cup  basin-shaped,  the 
bottom  deeply  excavated  and  truncated  to  near  the  top  of  the  second 
costals ;  the  sides  gently  curving  upward  to  about  a  vertical  position ;  the 


jielocrixid-t:. 


813 


nrm  bases  slightly  projecting  nnd  lobed,  giving  to  the  cross-section  nn 
obtusely  pentagonf.l  outline.  Ventnil  disk  low-pyramidal,  the  interauibu- 
lacral  spaces  llat  or  slightly  depressed,  nnd  the  plates  apparently  without 
ornamentation.  In  the  dorsal  cup  the  plates  are  traversed  by  a  large  num- 
ber of  very  fine  radiating  ridges,  passing  from  plate  to  plate,  four  to  five 
from  each  side,  which  are  well  defined  near  the  outer  margins  of  the  plates, 
but  become  more  indistinct  along  the  median  portions.  Interbrachial  plates 
a  little  convex,  the  plates  of  the  rays  from  the  margin  of  the  basal  concavity 
to  the  middle  of  the  second  co^tals  surmounted  by  keel-like,  very  conspicu- 
ous protuberances,  which  rise  from  the  lateral  margins  of  the  plates,  at  first 
very  gradually,  but  near  the  middle  of  the  plates  almost  perpendicularly, 
forming  knife-like  edges  at  the  outer  end.  The  ridges  are  continued  upon 
the  distichals,  but  above  the  costals  lose  their  knife-like  character. 

Basal  disk  small ;  restricted  to  the  lower  part  of  the  concavity,  which  is 
completely  filled  by  the  upper  end  of  the  colunni.  Radials  a  little  larger 
than  the  costals,  their  lateral  sloping  upper  faces  considerably  shorter  than 
the  corresponding  lower.  Distichals  two — sometimes  three  —  the  upper 
one  short  and  lunate,  supporting  the  primary  arms,  two  to  the  ray.  First 
interbrachial  larger  than  any  of  the  other  places,  nearly  as  wide  as  long; 
followed  by  a  good  sized  single  plate,  and  this  by  two  ranges  of  three  plates 
each,  which  rest  between  the  arm  bases.  In  the  tegmen  there  are  two  large 
cuneiform  plates  to  each  interambulacral  space,  which  are  faced  by  two  or 
more  smaller  pieces  with  four  slits.  Two  similar  plates  and  two  slits  overlie 
the  interdistichal  spaces.  Orals  large,  pushed  anteriorly.  Kadial  dome 
plates  quite  conspicuous ;  three  of  them  resting  within  the  re-entering  angles 
of  the  orals,  the  two  others  against  the  large  anal  tube. 

Horizon  and  Locality.  —  Upper  Helderberg  group ;  Falls  of  the  Ohio,  near 
Louisville,  Ky. 

Type  in  the  Lyon  collection,  Jeffersonville,  Ind. 

Remarks.  —  Lyon  described  the  basals  as  "horizontally  disposed,"  and 
"  not  concealed  in  the  pit."  We  conclude  from  his  type  specimen  that  he 
mistook  the  extended  outer  edges  of  the  top  stem  joint  for  the  margin  of  the 
basal  disk,  and  its  nucleus  for  the  column.  Another  specimen  in  the  Lyon 
collection  shows  the  inner  floor  of  the  basal  disk,  which  appears  to  be 
tripartite. 


./...^  /y-'^'^'f 


^    /.^.:  -i   /-  ^ 


40 


I 


314 


THE  CRIXOIDEA  CAMERATA  OF  NORTH  AMERICA. 


»l 


I       ' 


<  •: 


Dolatoorinus  Marshi,  var.  hamiltonensis  W.  and  Si>. 
Plate  XXV.  Fkjs.'M,h. 

A  form  very  similar  to  D.  Mamhi  occurs  in  the  Hamilton  group,  which 
we  distinguish  from  the  typical  Ibrm  as  variety  huiniltoncims.  The  basal  con- 
cavity is  shallower  and  narrower,  the  radial  ridges  knife-like,  and  occupy  the 
median  line  of  the  plates  instead  of  being  keel-shaped  and  rising  gradually 
from  the  outer  margins  of  the  plates.  The  ventral  disk  is  considerably 
lower,  and  but  slightly  convex ;  the  orals  smdiler,  the  posterior  one,  which 
is  very  short,  is  placed  so  as  to  form  at  the  anterior  side  the  base  of  the  anal 
tube.     All  plates  of  the  disk  covered  by  several  well  defined  tubercles. 

Ilorkon  caul  Loculiti/.  —  Hamilton  group.  Bear  grass  quarries,  Louis- 
ville, Ky, 

Type  in  the  collection  of  Mr.  Victor  W.  Lvon,  Jeffersonville,  Ind. 


Dolatoorinus  Lyoni  w.  and  Sr.  (nov.  sppc). 
Plate  XXV.  Fiijs.  6a,  h.,  c,  d. 

Calyx  rather  large,  considerably  wider  than  high.  Dorsal  cup  more  than 
twice  as  wide  as  high ;  the  basal  portions  deeply  impressed,  forming  a  broad 
funnel-shaped  cavity  which  includes  one  half  the  radials.  The  plates  above 
the  lirst  costals  curve  gradually  upwards,  and  the  two  upper  rows  stand  at 
right  angles  to  the  truncated  lower  part  of  the  calyx.  Ventral  disk  low- 
pyramidal,  slightly  grooved  toward  the  arm  bases ;  the  plates  flat,  covered 
with  numerous  small  pustules.  The  plates  of  the  dorsal  cup  are  grotesquely 
ornaiuented  with  a  variety  of  prominences  and  depressions ;  some  of  them 
elevat'.'d  into  sharp,  very  conspicuous,  transversely  rounded  nodes,  others 
sharply  pointed ;  and  from  all  of  them  somewhat  irregular,  subangular  ridges 
pass  out  to  the  margins  of  the  plates,  connecting  with  similar  ridges  from 
adjoining  plates.  The  plates  of  the  rays  have  no  nodes,  and  but  few  ridges 
proceed  upwards ;  those  directed  laterally  form  n  well  defined  pentagon 
around  the  basal  concavity.  In  the  upper  part  of  the  calyx  the  nodes  cover 
the  greater  part  of  the  plates,  and  the  ridges  are  merely  indicated  at  their 
outer  margins. 

Basals  small,  restricted  to  the  bottom  part  of  the  cavity.  Eadials  nearly 
as  large  as  the  two  costals  together.  First  costals  quadrangular,  narrower 
than  the  radials ;  the  second  pentangular,  supporting  upon  one  side  an  axil- 


■rii 


MKLOCRINIDyE. 


315 


lary  diHtichal  followed  by  3  X  2  paltnars  and  two  anna,  upon  the  oilier  three 
fixed  di.stielmls,  which  support  one  arm.  There  are  three  primary  arms,  two 
and  one,  to  the  ray;  two  of  the  simple  arms  facing  the  anal  intcrradiiis. 
Arm  openings  directed  obliquely  upwards,  less  projecting  and  smaller  than 
usual  in  the  genus.  Interbrachials :  1,  1,  3,  4  ;  the  first  large,  rather  angular 
below,  broadly  truncate  above,  the  upper  sides  a  little  wider  than  the  lower ; 
the  second  almost  as  large  as  the  first,  with  a  long  transverse  node.  The 
three  plates  of  the  thiid  row  much  smaller  and  provided  with  elongate  nodes. 
The  plates  of  the  fourth  row,  which  occupy  the  arm  regions,  are  small  and 
highly  convex,  their  upper  faces  pierced  by  the  lower  part  of  the  slits.  The 
interambulacral  plates  consist  of  five  large  cuncate  plates,  of  which  the  three 
middle  ones  are  larger  than  the  others ;  the  sides  of  the  outer  ones  excavated 
to  form  the  slits,  which  are  quite  large  in  this  species.  The  anal  intcrradius 
has  a  few  additional  plates  in  the  disk,  which  connect  with  the  anal  tube. 
Interdistichals  four  to  the  arm  region.s,  arranged  in  two  rows,  followed  by 
three  cuneate  interambulacral  plates,  with  two  slits,  while  there  are  four  slits 
above  the  interbrachial  spaces.  Orals  large,  all  of  similar  form  and  .size, 
surrounded  by  good  sized  radial  dome  plates  of  a  first,  second,  and  third 
order.  Anal  tube  almost  central,  its  base  formed  of  rather  large  convex 
plates. 

Horizon  and  Localili/.  — Upper  Helderberg  group  ;  Clark  Co.,  Ind. 

Ti/pcs  in  the  collection  of  Victor  W.  Lyon,  Jeft'ersonville,  Ind. 

Remarks.  —  This  .species  is  readily  distingui.shed  from  all  others  of  this 
genus  known  to  us  by  the  grotesque  st3'le  of  its  ornamentation. 


A/'i'  1 1 


6 


DolatoorinuB  canadensis  Whiteaves. 
Plate  XXV.Fifjs.  7a,  h. 

1SS7.    WiiiTEAVESj  Gcol.  mid  Nat.  Illst.  Surv.  Caimda;  Contrib.  to  Can.  rnlwont.,  Vol.  I.,  p.  99,  Plate  12, 
figs.  3,  3(7. 

Of  the  type  of  DoMocrinus  Marsld,  but  with  a  different  arm  foi-mula. 
Calyx  small,  much  wider  than  high.  Dorsal  cup  broadly  and  shallowlj- 
b.asin-shaped,  slightly  depressed  along  the  radials,  and  more  conspicuously  at 
the  basals.  "Ventral  disk  lower  than  the  dorsal  cup ;  hemispherical ;  the 
central  portions  slightly  tumid.  The  ornamentation  of  the  dorsal  cup  con- 
sists of  numerous  parallel  ridges,  passing  out  to  the  sides  of  the  plates,  and 
meeting  those  of  adjoining  ones.    The  rays  along  their  median  lines  followed 


316 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


/^.C/    A 


an 


/ 


d\    fl  ^^/  • 


by  broiul,  keel-like  processes,  which  form  into  a  knot  in  tlic  centre  of  the 
radiiils  lunl  .second  co'ttal.s.  Anotiier  prominent  ridge  runs  from  the  lower 
margins  of  the  first  interbrachiuls  to  tlie  middle  of  the  plates,  where  it  forms 
a  rather  sharp  node,  from  which  two  brandies  proceed  to  the  upper  lateral 
margins.  The  smaller  ridges,  of  which  there  are  three  to  four  to  each  side, 
are  marginal,  extending  but  a  short  distance  into  the  plates. 

Basals  small,  perfectly  anchylo.sed,  surrounded  by  a  circular  ridge,  and 
entirely  covered  by  the  column.  Radials  larger  than  the  costals,  hexagonal, 
wider  than  long,  widest  above  the  middle  and  not  visible  from  a  side  view. 
h  0  ^  First  costals  short,  quadrangular;  the  second  considerably  wider,  a  little 
.  longer  and  axillary,  giving  oflf  to  one  side  an  axillary  distichal,  which  sup- 
ports a  small  palmar  at  each  side,  and  this  an  arm.  The  opposite  distichal 
gives  off  a  single  arm  from  the  second  plate,  thus  making  throe  primary  arms 

to  the  ray.     Arm  bases  projecting,  giving  to  the  calyx,  as  seen  from  above, 

a  pentagonal  outline.  Structure  of  the  arms  unknown.  Interbrachials :  1,1, 
3;  the  first  large;  the  second  much  wider  than  high;  the  middle  plate  of  the 
third  row  compamtively  largo  ;  the  two  at  the  sides  as  long,  but  narrower. 
Ventral  disk  composed  of  but  few  large  plates,  which  arc  covered  with  several 
minute  pustules  of  irregular  arrangement ;  the  intcrambulacral  spaces 
dejjressed,  consisting  generally  of  only  two  plates,  wliiidi  abut  against  the 
orals.  Tlierc  are  no  interdistichals.  Orals  and  ambulacral  plates  arranged 
ns  in  the  preceding  species.     Anus  subcentral. 

Jlor'aon  and  Loca/iti/.  —  Hamilton  group;  near  Thedford,  Ontario. 

Ti/pe  in  the  Canada  Survey  Museum  at  Ottawa. 

Jicmar/iii.  —  It  is  barely  possible  that  Hall's  Cacahocrinus  Troosd,  from 
Western  New  York,  is  identical  with  this  species,  but  it  is  described  with 
four  primary  arms  instead  of  three. 


Dolatoorinus  triadactylus  Barris. 
Plate  XXVI.  Figs  4a-d. 

18S1.    Babbis;  Procped.  Davcnp.  Acad.  Nat.  Sciences,  Vol.  IV.,  Pinto  2,  figs.  5-7. 
1885.    W.  and  Sp.  ;  llcvision  Palajocr.,  Part  III.,  p.  105. 

Of  medium  size.  Cal^'x  depre.ssed,  a  little  wider  tlian  high.  Dorsal  cup 
broadly  basin-shaped  ;  the  lower  portions  truncate  to  near  the  top  of  the 
first  costals,  then  curving  rapidly  upwards,  a  little  constricted  below  the  arm 
bases ;   the   basals   moderately  excavated,  and   the  margin   of  the  cavity 


/ 


MKLOC'BINIDili:. 


317 


surrounded  by  a  circular  ridgo ;  tho  nrtn  bnsos  slightly  projecting.  Surfiicc 
covered  by  numerous  angular  ridges,  wliieli  radiate  from  centre  to  centre  of 
tho  plates,  producing  various  geometrical  figures.  The  ridges  connecting 
the  radials  form  a  pentagon  around  the  basal  pit,  which  is  radially  disposed 
and  of  which  tho  sides  support  five  triangles,  each  one  enclosing  a  smaller 
one.  The  outer  triangles,  together  with  the  pentagon,  fonn  a  live-rayed 
star,  and  tho  spaces  between  the  rays  of  this  star  are  also  formed  into  tri- 
angles, which  are  followed  by  other  triangles  above. 

Basals  small,  resting  completely  within  the  columnar  depression.  Radials 
and  costals  of  eqnal  height,  but  the  first  costal  narrower  than  the  second. 
The  latter  supports  at  one  side  an  axillary  distichal,  followed  by  two  small 
palmnrs  and  two  arms,  and  at  the  opposite  side  by  two  successive  distichnls  and 
a  single  arm,  making  three  arms  to  tho  ray.  Arms  stout,  biserial,  not  bifur- 
cating at  the  lower  ends ;  their  upper  parts  unknown.  Arm  joints  short, 
with  parallel  faces.  First  interbrachial  largo,  supporting  a  smaller,  sub- 
quadrangular  plate,  and  three  plates  in  the  third  row,  which  in  turn  are 
followed  by  five  cuneate  plates,  which  extend  above  tho  level  of  the  arm 
regions.  At  the  four  regular  sides,  the  throe  middle  ones  of  those  plates  are 
considerably  larger  than  the  outer  ones,  and  touch  the  orals ;  at  the  anal 
side  they  are  followed  by  a  few  additional  plates,  which  abut  against  the 
anal  tube.  Interdistichals  .small,  consisting  of  three  pieces,  succeeded  by 
two  interambniacral  plates  forming  two  slits.  The  number  of  slits  at  tho 
interradial  spaces  cannot  be  ascertained  from  the  specimens.  Ventral  disk 
.slightly  tumid  ;  the  interambniacral  spaces  depressed,  the  plates  almost  fiat, 
the  orals  and  radial  dome  plates,  which  are  somewhat  larger,  covered  with 
small  but  sharp  nodes.  Anus  snbcentral.  Column  round,  with  crenulated 
edges ;  axillary  canal  pentangular. 

If'irizoii  mid  Loriill/i/.  — Hamilton  group  ;  Alpena,  Mich. 

Ti/j)es  in  the  Museum  of  the  Davenport  Academy  of  Sciences. 


V   y'''  '<^ 


^  J 


■"'V     " 


.  .y  , 


Dolatocrinus  glyptus  (TT.vi.i.). 
Plaie  XXVI.  Figs.  2a,  b. 

1802.     Ca.aljnrriiiun glyptus  — \\.K\.\.;  15lli  Hop.  N.  Y.  Stntc  Cab.  Nnt.  Ilist.,  p.  liO. 
1S81.     ])ii!iili>''i-iiitt.i  fili/iitiix  —  \V.  niid  Sn. ;  Revision  Piilirncr.,  I'nrf  II.,  p.  125. 

Syii.  Cimihofriiiim  filj/plii«,  vnr.  intrrnifiHus  IIam,  ;  l^Sl,   15tli  Keg.   Rep.  N.  Y.  State  Cab.  TCat. 
Hist.,  p.  lU.'  ' 

Syn.  Duliilocriniis  ornalm  Meek;  1871,  Proceed.  Acad.  Nat.  Sci.  PLUa.,  p.  57. 


318 


THE  CRINOIDEA  CAMERATA  OF  NOUTH  AMERICA. 


/ 


P' . 


....  t'. 


(A  '"'• 


;  'I 

■;  ',1 


Larger  timii  any  of  the  prccediiij^  species.  Ciilyx  »le[)resse(I-yiobose, 
soinewliat  llattoneil  to  near  the  top  of  tlie  radials;  rapidly  curving  above,  so 
that  tiie  walls  of  the  dorsal  cup  near  the  arm  bases  arc  parallel  to  those  of 
the  opposite  side.  Plates  ornamented  by  interrupted  ridges  or  lines  of 
small  nodes,  some  of  them  radiating  to  the  angles  of  the  plates,  others  to  the 
sides  ;  those  passing  fiom  the  basal  pit  to  the  nnn  bases  the  strongest  and 
almost  continuous,  rising  to  angular  nodes  in  the  centre  of  eacli  plate.  First 
interbrachial  provided  with  a  strong  central  tubercle,  and  the  ridges  pro- 
ceeding from  the  radials  to  the  first  disticlmls  more  prominent  than  the 
others.     Suture  linos  slightly  channeled. 

Basal  disk  comparatively  large,  the  upper  angles  projecting  l)oyond  the 
column,  the  median  portions  concave,  and  the  cavity  surrounded  by  a  cir- 
cular rim.  Radials  considerably  wider  than  the  costals,  and  also  wider  than 
long.  First  costals  twice  as  wide  as  long,  the  lower  faces  distinctly  convex, 
the  upper  a  little  concave.  Second  costals  longer  than  the  first,  slightly 
increasing  in  w'''h  upwards,  the  sloping  upper  faces  obtusely  angular. 
Distichals  2X2;  the  first  equal  to  two  thirds  the  size  of  the  axillary  costal ; 
the  two  of  the  second  row  not  more  than  half  the  size  of  the  first,  and  those 
of  the  second  row  separated  by  an  interdistichal.  Palmors  two,  short,  lunate, 
supporting  the  two  primary  arms.  First  interbrachial  almost  as  large  as  any 
two  other  plates  of  the  calyx,  and  nearly  as  wide  as  long ;  followed  by 
a  comparatively  large  hexagonal  plate,  which  supports  three  others ;  the 
two  at  the  sides  elongate  and  smaller  than  the  middle  one.  Ventral  disk 
depressed-pyramidal.     Anal  tube  subcentral,  rising  gradually  from  the  disk. 

Horizon  and  Locality.  —  Hamilton  group ;  near  Pavilion,  Genessee  Co., 
N.  Y.,  and  Columbus,  0. 

Tf/pe  in  the  American  Museum  of  Natural  History,  New  York. 

Remarks.  —  We  regard  Cacahocrinus  gh/jitm,  var.  intermedins,  described 
by  Hall,  and  Dolatocrinus  ornatas  Meek,  as  mere  variations  of  D.  glyptun,  the 
specimons  only  differing  a  little  in  the  ornamentation.  In  the  typical 
D.  (jhiptus,  the  ridged  upon  ;he  plates  are  not  continuou.s,  but  consist  of 
irregular  series  of  elongate  nod'js;  while  in  the  specimens  of  Z).  (jJijptits,  var. 
intcrmedius  they  are  generally  not  interrupted.  D.  ornatus  was  described  by 
Meek  as  coming  from  the  Hamilton  group  of  New  York. 


MELOCRINIIU:. 


819 


DoIatoorinuB  liratuB  (IIali). — 

riatcXXVJ.  Flij.J. 

ISfli.     Ciidilmi'riHua  lirii/iit  —  llvl.i, ;  l.")tli  lli'|p.  N.  Y.  Slal.:  Cub.  Nul.  lli«l  ,  p.  l:)9. 
1^?«1.     Jhliiiiii'intun  lifdlm  —  W.  mill  S|i.  ;   Ilcihiim  I'lilii'ijcr.,  I'lirt  II.,  |i.  \ifi. 

Sjii.  t'lifabucriima  liiutHi,  var.  mullilira  —  IIaI.1.  ;   l.'illi  l(<|i.  N.  V.  filalc  C'lil).  Nut.  Hisl.,  p.  139. 

Very  closely  resembling  D.  t/h/phin,  nnd  probably  a  mere  viiricty  of  tlint 
Hpecies.  The  speciiuens  referred  to  the  latter  by  Hall  are  nliorter  nnd  tlieir 
bnMul  portions  more  deiJre.-^Hed,  but  this  niny  possibly  be  due  to  pressure. 
They  agree  in  the  Ibrni  and  arrangement  of  the  plates,  and  both  havf  two 
primary  urms  to  the  my,  a  depreM.sed  ventral  disk,  ridges  along  the  ambu- 
lacra, and  nn  almost  central  anal  tube.  The  only  perceptible  diflerence  is  in 
the  style  of  ornamentation.  The  ridges,  which  in  J).  ijIiijUuh  are  more  or 
less  interrupted,  are  continuous  in  J),  lintfns.  It  has,  besides,  large  ridges 
radiating  from  the  centre  of  the  plates  to  each  of  tlieir  angles,  and  three  to 
live  smaller  ridges  pa.ssing  out  to  the  sides,  where  they  join  with  similar 
ridges  from  adjacent  plates.  The  plates  of  the  ventral  disk  are  densely 
crowded  with  large  and  small  prominences,  similar  to  those  found  in  certain 
species  of  Amp/ioracrlnKfi. 

Horizon  anil  LocaJitij.  —  The  same  as  the  preceding  species. 

Tjpc  in  the  New  York  State  Cabinet  of  Natural  History  at  Albany. 

Dolatoorinus  ioosidactylus  av.  and  Si-.  (nov.  speo.). 
riatc  XXV I .  Fitjs.  Sa-d. 

A  large  and  greatly  depressed  species  of  the  type  of  D.  ffl'//>fus,  but 
readily  distingui-shed  by  having  four  instead  of  two  primary  arms  to  the  ray. 
When  not  crushed,  the  calyx  to  the  base  of  the  anal  tube  only  about  four 
fifths  as  high  as  wide,  but  it  appears  to  be  still  shorter  in  the  usual  preserva- 
tion. Dorsal  cup  twice  as  high  as  the  tegmen,  broadly  cup-shaped,  ilattened 
to  the  top  of  the  costals,  and  the  basals  formed  into  a  funnel-slinped  cavity, 
surrounded  by  a  circular  ridge.  The  median  lines  along  the  plates  of  the 
rays  to  the  bases  of  the  arms  elevated  into  prominent  ridges,  nnd  the  middle 
of  each  radial  and  costal  crowned  by  a  small  central  node.  The  nodes  are 
directed  longitudinally ;  they  are  in  some  specimens  r|uite  conspicuous,  while 
the  ridges  are  almost  obsolete ;  in  others,  however,  the  ridges  are  almost  ns 
high  ns  the  nodes.     Smaller  ridges,  or  more  properly  speaking,  rows  of  elon- 


/.^  '• 


.   .Iff/ 


/.  ■  >' 


/ 


'    \ 


820 


TIIK  CHINOIDKA   CAMKIIATA   Ol'   NOHTII   AMKIUCA. 


I       I 


'.  0-'/  ;■ 


.21 

^1    <  ■^  •'»  I/- 


giitu  noduN,  railiiito  U'm\  tiuiir  tlio  iiiiilillo  of  tliu  mdiiilM  iind  coHtalH  to  (lie 
turgor  iiiturbriicliiiiirt,  tlio  latter  hiiviiig  guiicM-iilly  four  hucIi  ridgCH  to  ouch 
«ido  of  tlie  pliitu,  urraiigcd  paralli'l.  Toward  tlio  iipptT  part  of  tlio  dorwil 
cup  tlie  ridj,'ox  almost  di;mi)pL'ar,  and  tlio  plates  iiro  nimply  tumid. 

Hasal  disk  dcpri'ssi-d  fiiiiiR'l-sli.ipi'd  ;  tliu  outer  rim  on  a  level  with  the 
rudials;  pi'rforatod  by  u  lurgo,  i)eiitalohato  canal  with  nharp  re-entering 
nngloH,  which  extend  deeply  inward.  Ihidialft  larger  than  the  costals,  their 
length  equal  to  the  width  at  the  lower  end;  the  truncated  upper  faces  con- 
cave; the  sloping  upper  faces  nuieh  shorter  than  the  sloping  lower.  First 
costaln  Mul)(iu'ulrangular,  narvovver  than  theradials;  upper  and  lower  sides 
convex.  Second  costal-*  very  little  wiiler,  hut  considerahly  longer  and  pen- 
tangular. Distichuls  1X10;  all  axillary;  almost  ns  large  us  tho  Hccoiid 
cotttuls.  Pulnuirs  much  smaller,  the  two  lower  ones,  which  arc  short  and 
lunate,  incorporated  into  the  oalyx.  Arm  openings  arranged  in  groups ; 
large  ;  directed  ol)li(|uely  upwanls.  Primary  arms  twenty,  Interl)rachial 
spaces  wide,  the  plates  arranged  ;  1,  1,  2;  the  first  larger  than  the  radials; 
the  second  almost  ns  largo  ns  tho  rust  costnis,  suhqiiadrnngular ;  the  two  of 
the  third  row  much  smaller.  Uetween  the  nrm  openings  are  three  to  five 
minute  pieces,  which  are  followed  by  two  large  elongate  plates  in  the  teg- 
men,  and  several  additional  plates  at  the  anal  side.  There  are  four  slits  to 
each  interradial  space,  and  the  saiiie  number  to  each  interdistichal  space. 
Ventral  disk  low-heiuispherieal,  surmounted  by  n  medium  sized  almost  cen- 
tral tube;  the  course  of  the  ambulacra  marked  by  an  clevntion,  tho  inter- 
ambulacral  spaces  depiossed,  especially  neiu'  the  outer  margin ;  tho  plates 
completely  covered  with  small  pustules  of  even  size.  Orals  and  ambulacral 
plates  us  usual  in  the  genus.  Column  round,  the  joints  with  slightly  waving 
edges,  and  rapidly  increasing  in  size  downwards;  the  nodal  joints  projecting. 

Horizon  and  Locallfij.  —  Hamilton  group  ;  Louisville,  Ky. 

Types  in  the  collodion  of  Wachsmuth  and  Springer,  and  Victor  W.  Lyon. 

liemarks.  —  This  s])ecies  bears  some  resemblance  to  "  Cocahocriiiiis  " 
hoHcUustis  Hall ;  but  differs  considerably  in  the  form  and  size  of  the  basal 
depression,  which  in  the  latter  species,  according  to  Hall,  is  large,  sub- 
circular,  and  embraces  the  basals  and  one  third  of  the  radial  plates.  It  also 
occurs  at  a  different  geological  horizon. 


Mi'.i.ocuiNih.i;. 


321 


Dolatoorinui  exoavatui  w.  im.i  sv.  (mv.  Bpoc). 
I'laf.   A' AT.  Fi>j.  /,  and  I'lat,  WW  I.  Fl./x.  T  in„l  S. 

A  very  lnrj(o  HpocicH.  Doi'kiiI  cup  »ihiiIIow-biinin  hIhuhmI,  llin-o  timoH  nn 
wido  M  higli ;  lliu  bottom  llatt(MUMl  to  tlio  t()|)  of  tlio  ooxtals;  tlio  niiIch 
convex,  rnpiilly  curvinj^  iipwiinlM,  II  littlo  constrictcil  iit  tlic  arm  Imson;  f|ii> 
radiiils  formud  into  a  deep,  nliarply  pentangular,  rimnel-Nliii[ii>d  pit,  which 
ponotratoH  tho  calyx  almost  to  tlio  heigiit  of  the  arm  ro;>ionH.  Siirfacu  of 
platen  —  except  those  in  tho  j)it  —  covered  with  parallel  riilgen,  radiating 
from  tho  centre  of  the  plates  to  their  sides,  whore  they  meet  with  wimilar 
ridges  from  ailjoining  [)lates.  In  addition  to  these  ridges  there  are  keel-liko 
projections  following  the  radials  and  costals,  which  grow  more  conspicuous 
downward,  and  at  about  the  top  of  the  radials  are  produced  into  a  tubercle, 
which  projects  into  the  funnel-shaped  pit,  nnd  gives  its  npi)er  margin  a 
slightly  stellate  outline.  Occasionally  the  carinate  ridges  arc  continued  to 
the  higher  brachials,  but.  as  a  rule,  they  becoino  obsolete  above  the  second 
costals.     Suture  lines  slightly  grooved. 

Basals  elongate  ;  forming  together  with  the  radials  a  highly  elevated 
inverted  cone  with  a  large  pentalobatc  canal.  Radials  large,  once  and  a  half 
ns  long  as  wide ;  four  fifths  of  tho  plates  taking  part  in  tho  pit,  tlic  other 
fifth  bending  al)ruptly  outward  ;  upper  sloping  faces  short ;  the  lower  faces 
eqiud  to  one  half  the  greatest  width  of  the  plates.  First  costals  small,  twice 
ns  wido  as  long,  tluir  upper  and  lower  faces  convex.  Second  costals  wider 
than  long  and  slightly  wider  than  the  first.  Distichals  four;  tho  first  os 
largo  as  the  two  costals  together.  Arnis  two  to  the  ray,  about  equidistant. 
First  interbrachial  slightly  curving,  larger  than  the  radials  and  first  costals 
together,  elongate,  widest  across  the  middle  of  tho  plate ;  angular  at  both 
er.  Is;  the  lower  end  bending  inward  so  as  to  form  a  part  of  the  pit.  There 
nre  two  largo  plates  in  tho  second  row,  three  smaller  ones  in  the  third,  and 
these  arc  succeeded  by  a  row  of  six  elongate  pieces  in  the  ventral  disk,  and 
two  additional  larger  plates  which  abut  against  the  orals.  Interdistichals 
one  or  two  in  the  dorsal  cup,  followed  by  five  or  six  small  pieces  in  tho 
togmen,  and  a  larger  one  between  the  secondary  radial  dome  plates.  Slits 
six  to  each  interradial  space,  and  four  to  each  interdistichal  one.  Ventral 
disk  depres.sed,  slightly  tumid  ;  the  interambulacral  spaces  flattened,  and 
sometimes  a  little  depressed,  producing  indistinct  ridges  along  the  ambulacra. 

41 


WICJM  WWtl— 


"T^WFayr  .""mmmp^ 


322 


THE  CKIXOIDEA  CAMEIIATA  OF  XOUTJI   AMEIUCA. 


I^'i! 


if 


0, 


.....     n...^    ^f- 


/    - 


,ch 


fi-  /:>' 


:    I 


Orals  large ;  the  posterior  one  small  and  lunate,  owing  to  the  almost  central 
position  of  the  large  anal  tube. 

Horizon  and  Zoailltij.  —  Upper  Ileldcrborg ;  Clink  Co.,  Ind, 

T;/j)cs  in  the  collection  of  Victor  W.  Lyon. 

RcmarJcs.  —  Differing  from  all  othei  known  species  of  this  genus  in  the 
great  size  of  the  calyx,  tlie  form  and  depth  of  the  basal  pit,  in  having  two 
secondary  interbrachial.^,  and  in  the  number  of  the  slits.  The  specimen  on 
Plate  XXVI.,  Fig.  7,  exhibiting  the  inner  Loor  of  the  disk,  is  very  interest- 
ing as  showing  the  counuunication  of  the  slits  with  the  inner  cavity. 

DolatOOrinuS  major  AV.  and  Sp.  (nov.  spec). 
Plate  XXV.  Fiff.S. 

A  very  large  .species,  in  general  form  resembling  the  preceding,  but  with 
a  shallow  ba.sal  depression,  four  arms  to  the  ray,  and  without  surface  orna- 
mentation. Dorsal  cup  depre.ssed-bowl-shaped,  almost  three  times  as  wide  as 
high,  flattened  below ;  the  radials  and  part  of  the  costals  stretched  out  hori- 
zontally ;  the  basals  forming  a  shallow  concavity  surrounded  by  a  thickened 
rim;  the  sides  gently  bending  upwards  and  becoming  parallel  at  the  top  of 
the  first  distichals.  The  plates  are  smooth,  with  the  exception  of  a  small 
rounded  node  upon  the  two  costals ;  that  of  the  first  costal  occupying  the 
upper  end  of  the  plate,  that  of  the  second  the  median  part.  Radials  compar- 
atively small,  con.siderably  wider  than  long ;  the  upper  and  lower  lateral 
faces  almost  equal ;  the  lower  margin  thickened  and  forming  a  rim  around 
the  basal  concavity.  First  costal  as  large  as  the  radials ;  the  upper  face 
decidedly  convex,  and  the  lateral  ones  slightly,  but  the  lower  face  straight. 
Second  costal  larger  than  the  first,  broadly  pentangular.  Distichals  1  X  10 ; 
large ;  axillary ;  supporting  two  good  sized  fixed  palmars,  and  these  the 
free  arms.  Arms  twenty,  arranged  at  almost  equal  distances  around  the 
calyx.  Interbracbial  spaces  somewhat  depres.sed  at  their  lower  ends,  and 
slightly  receding  between  the  arm  bases ;  the  first  plate  large,  its  upper  half 
considerably  wider  than  the  lower  half,  its  upper  face  truncate  and  somewhat 
concave.  The  plate  of  the  second  row  is  approximately  as  large  as  the  first 
costals,  but  higher  than  wide  and  hexagonal ;  the  lower  lateral  faces  parallel, 
the  upper  lateral  ones  sloping.  There  are  three  plates  in  the  third  row,  and 
others  above.     Interdistichals  one.     Structure  of  the  ventral  disk  unknown. 

Horizon  and  Locality.  —  Upper  Helderberg  group ;  Falls  of  the  Ohio. 

Type  in  the  collection  of  Victor  W.  Lyon. 


Will 


"&i 


:'  i 


BIELOCRIXID.E. 


323 


Dolatoorinus  speoiosus  (Hall). 
Plate  XXV.  Figs.  4a,  b. 

1802.     Cacalocriiiiia  speeiosus  —  Hall  ;  IStli  Rop.  N.  Y.  Slate  Cab.  Xiit.  Ilist. ,  p.  V67, 
1881.    Ihlatocriiius  speciuniis  —  W.  and  Sp.  ;  lU'visioii  I'alii'ncr.,  p.  12G. 

Of  the  type  of  D.  major,  but  smaller;  the  dorsal  cup  proportionally 
hiylicr,  and  provided  with  a  somewhat  deeper  basal  pit;  the  radials  instead 
of  being  stretched  out  horizontally,  gradually  slope  toward  the  basal  con- 
cavity, without  actually  forming  a  part  of  it.  It  has  but  two  distichals,  and 
two  arms  to  the  ray  instead  of  four ;  arranged  in  pairs  with  wide  interspaces. 
Cress-section  below  the  arm  regions  subpontangular.  Plates  apparently 
without  ornainentiition,  their  surfaces  slightly  convex;  tUe  median  line  of 
the  plates  following  the  rays  gradually  rising  into  a  keel-like  projection  or 
carina,  which  passes  up  to  the  bases  of  the  arms.  This  carina  is  higher  upon 
the  radials  and  costals,  and  thickened  at  the  middle  of  each  plate,  where  it 
is  formed  into  a  conspicuous  elongate  node ;  the  node  of  the  fust  costals 
more  prominent  than  the  others. 

Basals  small,  forming  a  shallow  inverted  basin,  which  is  completely  filled 
by  the  column.  Radials  larger  than  the  costals,  and  about  as  wide  as  long. 
The  first  costal  narrower  and  shorter  than  the  second,  and  quadrangular ; 
the  second  obtusely  angular  above.  Distichals  2  X  10,  comparatively  large  ; 
followed  by  a  lunate  arm  plate.  Arm  openings  two  to  the  ray,  directed 
obliquely  upwards,  and  those  of  the  same  ray  packed  closely  together.  First 
interbrachial  almost  as  wide  as  long,  with  an  obtuse  lower  angle,  and  its 
upper  face  broadly  truncated  ;  the  second  about  half  the  size  of  the  first,  its 
lateral  faces  parallel.  The  latter  supports  three  plates,  two  upon  its  sloping 
lateral  sides,  and  one  upon  the  truncated  upper  face,  which  are  followed  by 
a  row  of  interambulacral  pieces.  The  interdistichal  spaces  contain  two 
plates.  Ventral  disk  slightly  convex,  each  side  containing  four  interambu- 
lacral plates,  two  of  them  larger  and  cuneate,  touching  the  orals,  the  two 
smaller  ones  abutting  against  the  secondary  radial  dome  plates.  The 
posterior  oral  is  deeply  wedged  in  between  the  four  others,  and  considerably 
shorter.     Anus  almost  central. 

Horizon  and  Locality.  —  Upper  Ilelderberg  group  ;  Western  New  York. 

The  specimen  figured  is  from  the  collection  of  Wachsmuth  and  Springer. 


/ 


A- 


e.-.-^^  ^'^ 


324 


tup:  crinoidea  camerata  of  north  America. 


Dolatocrinus  tuberoulatus  w.  and  Sp.  (nov.  spec). 
Plate  XXV.  Fig.  3. 

Of  the  type  of  D.  (jlyjitus  Hall,  but  dillering  in  the  style  of  ornamenta- 
tion. Dorsal  cup  not  twice  as  wide  as  high ;  subglobose,  slightly  depressed 
from  the  middle  of  the  radials  downward ;  central  concavity  small,  elliptical, 
formed  by  the  basals  only,  and  completely  filled  by  the  upjier  column  joints. 
The  radials,  costals  and  first  interbrachials  are  each  elevated  into  a  large, 
very  conspicuous  tubercle,  and  the  tubercles  are  connected  by  well-marked 
ridges.  There  are  generally  four  parallel  ridges  from  the  interradial  to  the 
radial  nodes,  and  the  same  number  between  the  radials  and  first  costals, 
which  form  five  sets  of  four  triangles  around  the  coluum  at  some  distance 
from  it;  those  of  tlie  same  set  concentric.  The  costals  are  connected  with 
the  first  interbrachial  by  two  ridges,  while  there  is  but  one  ridge,  but  more 
prominent,  between  the  distichals.  Other  ridges  connect  the  distichals  with 
the  higher  interbrachials.  Basal  disk  small,  almost  completely  hidden  by 
the  column,  and  surrounded  by  a  prominent  circular  rim  with  small  nodes 
interradially  disposed.  Radials  large,  almost  as  long  as  wide,  much  larger 
than  the  first  costals;  the  second  costals  higher  and  wider  than  the  first. 
Distichals  apparently  two,  each  one  provided  with  a  short  node.  First  inter- 
brachial smaller  than  usual  in  this  genus ;  followed  by  a  quadrangular  plate 
in  the  .second  row,  and  three  smaller  plates  above.  Nothing  is  known  of 
ventral  disk  and  arms. 

Horizon  and  Lociditij.  —  Hamilton  group ;  Clark  Co.,  Ind. 

Ti/pe  in  the  collection  of  Mr.  Victor  W.  Lyon. 

STEREOCRINUS  Barris. 

1S7S.  BvnnTs;  Proceed.  D.iTciiport  Acad.  Nat.  Sciences,  Vol.  II.,  p.  282. 

1881.  \V.  and  Sp. ;  Uevision  Palicoer.  Part  II.,  p.  126  (Proceed.  Acad.  Nat.  Sciences,  Pbila.,  p.  300). 

1885.  B.^iiiiis;  Proceed.  Davenport  .\oad.  Nat.  Sciences,  A'ol.  IV.,  p.  103. 

1889.  S.  A  Miller;  North  Amcr.  Geol.  and  Palieont.,  p.  283. 

In  general  form,  ornamentation,  and  the  arrangement  of  plates  resem- 
bling Doladtcrlnus,  but  having  one  costal  instead  of  two,  and  a  tripartite 
base.  Dorsal  cup  depressed,  truncate  below.  Basal  disk  small,  pentagonal ; 
composed  of  three  pieces,  of  which  the  suture  lines  are  generally  visible. 
Radials  and  costals  nearly  of  equal  size ;  the  former  hexagonal,  the  latter 
pentagonal  and  axillary.      Distichals  two  or  three,  supporting  the  arms. 


1 

1 

■  1 

i      •-] 

A 

in 

1 


MELOCRINIDiE. 


325 


T 


Arm  openings,  so  far  a^  observed,  two  to  the  ray ;  arms  biserial.  Interradial 
spaces  wide,  containing  three  ranges  of  plates  in  the  dorsal  cup ;  the  first 
and  second  range  composed  of  one  plate  each ;  the  third  of  two  or  three ; 
followed  by  large  cuneate  plates  in  the  disk.  Ventral  disk  rather  flat,  the 
interambulacral  spaces  depressed,  containing  one  or  more  slit-like  openings 
at  each  side  of  the  arms.  Ambulacra  subtegminal,  but  their  course  indicated 
by  elevations  upon  the  disk.  Orals  large  and  arranged  as  in  Bolatucrimis. 
Anus  subcentral,  apparently  at  the  upper  end  of  a  tube.  Colunm  round ; 
central  canal  large  and  pentalobate. 

Distfihution.  —  This  genus  has  been  observed  only  in  Michigan  and  Iowa. 
The  typical  species  came  from  the  Hamilton  group ;  but  we  have  in  our 
collectioi.  a  specimen  apparently  of  another  species,  from  rocks  considered 
to  be  Upper  Ilelderberg,  of  Waterloo,  Iowa;  it  is  not,  however,  sufficiently 
perfect  for  description. 

Rtereooriaus  triangulatus  Bakris. 
Plate  XXV.  Figs.  8a,  b. 

1S78.    BvBRis;  Proceed.  Davenport  Acad.  Nat.  Sciences,  Vol.  II.,  p.  2B1,  Plate  11,  Figs.  1,  2. 
1881.     W.  and  Sp.  ;  Revision  Palococr.,  Part  II.,  p.  127. 

A  rather  large  species.  Dorsal  cup  shallow-basin  shaped,  twice  as  wide 
as  high ;  the  truncate  lower  part  formed  by  the  basals,  radlals,  the  larger 
half  of  the  costals,  and  a  large  part  of  the  first  interbrachials;  the  lateral  walls 
of  opposite  sides  nearly  parallel ;  the  extreme  upper  end  slightly  constricted, 
and  the  interradial  spaces  a  little  depressed  between  the  arm  bases.  Orna- 
mentation re-^embling  that  of  Dnlatocnnus  trkdactijlus,  the  surface  being 
covered  by  similar  sets  of  parallel  ridges,  but  less  prominent.  Only  one  of 
each  set  passes  from  centre  to  centre  of  the  plates,  the  others  being  inter- 
rupted. By  means  of  these  ridges  the  whole  surface  of  the  dorsal  cup  is 
divided  up  into  numerous  triangles,  each  one  enclosing  one  or  two  smaller 
ones.  There  are  five  such  sets  of  triangles  around  the  basals,  three  to  each 
set,  and  similar  triangles  are  formed  in  the  upper  part  of  the  calyx. 

Basals  largely  projecting  beyond  the  column ;  central  canal  large,  penta- 
lobate. Radials  a  little  larger  than  the  costals,  all  wider  than  long.  Dis- 
tichals  2  X  10 ;  the  first  rather  large  ;  the  second  short,  lunate.  Arm  bases 
projecting,  arranged  in  pairs.  Arms  two  to  the  ray;  their  structure  un- 
known. First  intcrbrachial  a  little  larger  than  the  radials ;  the  second  about 
half  the  size  of  the  first,  followed  by  two  or  three  plates  in  the  third  row, 


1 


•msFm  '■'■vmmm:; 


/- 


326 


THE  CRIXOIDKA  CAMEllATA  OF  NORTH  AMERICA. 


1!      i 


and  a  number  of  small  plates  in  the  ventral  disk.  Disk  dcpressed-hemi- 
splioric ;  tiic  interanibulacrul  spaces  nearly  on  a  level  with  the  ambulacra ; 
all  tiic  plates  s]i<;htly  convex.  Anal  tube  large  at  the  base,  and  almost 
central. 

Horizon  and  Localiti/.  —  Hamilton  group ;  Davenport,  Iowa. 

7}/j)fs  in  the  Museum  of  the  Davenport  Academy  of  Sciences. 

lioiun-ks.  —  The  small  specimen  which  Barris  described  as  variety  "lira- 
tus,"  is  in  our  opinion  not  sufficiently  distinct  for  separation,  and,  it  ><eems  to 
us,  the  ditferences  given  are  readily  explained  by  individual  growth. 

Stereoorinus  Barrisi  w.  and  Si-.  (nov.  spec). 
Plate  XXV.  Figs.  Da,  h. 

Svn.  Slereocriiiiis  triunijidutus  Bauris  (in  part). 

Of  medium  size.  Calyx  more  than  once  and  a  half  as  wide  as  high, 
flattened  to  the  top  of  the  radials,  and  .slightly  depressed  at  the  basals ;  the 
sides  from  the  middle  of  the  costals  rising  vertically ;  lobed  at  the  arm 
bases.  Ventral  disk  short,  slightly  tumid,  the  interambulacral  spaces  deeply 
depressed  so  that  the  ambulacral  regions  are  conspicuously  elevated.  Plates 
of  the  dorsal  cup  covered  by  similar  .sets  of  triangles  as  in  the  preceding 
species,  but  the  ridges  forming  them  more  prominent,  and  there  is  a  node  in 
the  centre  of  each  plate ;  suture  lines  difficult  to  see.  The  column  is  sur- 
roun<led  by  a  strong  circular  ridge. 

Basal  disk  projecting  beyond  the  column.  Radials  and  costals  nearly 
equal  in  size,  the  former  hexagonal,  the  others  heptagonal.  Distichals  three 
in  the  calyx ;  the  first  a  third  the  size  of  the  costals ;  the  .second  and  third 
extremely  short,  the  latter  facing  laterally.  First  interbrachial  very  large, 
the  two  of  the  second  row  much  smaller.  Ambulacral  openings  large,  elon- 
gate. Respiratory  pores  four  to  each  interradius,  and  two  above  the  inter- 
distichal  spaces.  Orals  rather  large,  slightly  tumid,  pushed  to  the  anterior; 
the  posterior  one  resting  against  the  b.ise  of  the  anal  tube,  which  is  almost 
central.  The  plateu  covering  the  food  grooves  small  and  tuberculiform  ;  the 
interambulacral  ones  somewhat  larger  and  almost  flat.  Column  small,  round; 
the  axial  canal  large  and  pentalobate. 

Ilorizim  and  Localiti/.  —  Hamilton  group  ;  Alpena,  Mich. 

Tffpes  in  the  Museum  of  the  Davenport  Academy  of  Sciences,  and  in  the 
collection  of  Wachsmuth  and  Springer. 

Eemarks,  —  This  species  has  close  affinities  with  the  preceding  one,  and 


1    I 


MELOCRIXIU^E. 


327 


Barris  apparently  rogardot!  the  two  forms  as  representing  the  same  species. 
How  iver,  on  examining  a  largo  nnmber  of  specimens  of  both  types,  wo  find 
a  separation  necessary.  In  »S'.  Batrtsi  the  basal  disk  is  small,  extending  but 
slightly  beyond  the  column,  and  the  facet  for  the  reception  of  the  column  is 
surrounded  by  a  heavy,  circular  rim.  In  S.  trkuKjidatus  the  disk  is  qnite 
large,  the  top  stem  joint  occupying  less  than  half  its  diameter,  and  it  has  no 
rim  around  the  fticet.  The  interambulacral  spaces  of  .S'.  Barrisi  are  much 
more  depressed,  the  ambulr.cra  more  abruptly  protruding,  the  orals  larger, 
and  the  interambulacral  plates  flat  and  less  numerous. 

HADROCRINUS  Lvon. 

1809.    Lyon  ;  Trniis.  Amcr.  Philos.  Soc,  Vol.  XIII.,  p.  445. 

1881.     W.  niul  Si'. ;  Proceed.  Acad.  Nat.  Sci.  Pliihi ,  p.  396  (Revision,  Part  II.,  p.  222). 

1889.    S.  A.  Miller;  N.  A.  Geol.  and  PaliBonl.,  p.  252. 

Calyx  very  large ;  the  dorsal  cnp  saucer-shaped,  its  lower  portions  con- 
cave. Basals  small,  completely  covered  by  the  column  and  placed  at  the 
bottom  of  the  cavity  ;  they  are  closely  anchylosed,  and  their  suture  lines  are 
visible  only  upon  the  inner  floor.  Radials  pentangular,  the  lower  half  bent 
inward,  the  upper  stretched  outward.  Costals  one,  pentagoniil.  Distichals 
and  palmarsaro  always  represented  in  the  calyx,  and  sometimes  post-palmars; 
each  order  by  two  to  four  successive  plates  of  the  same  size  as  tiie  costals ; 
the  uppermost  plate  excavated  to  form  a  facet,  which  is  directed  laterally, 
and  supports  the  arms.  Interbrachials  variable  in  number  and  irregular  in 
their  arrangement,  as  large  as  the  adjoining  brachials.  The  anal  side  may, 
or  may  not  have  an  additional  plate  in  the  second  row.  Interdistichals  one 
to  three,  longitudirially  arranged,  as  large  as  the  interbrachitils.  Structure 
of  ventral  disk,  arms  and  anus  unknown.  Column  very  large  near  the  calyx 
(Lyon),  round,  tapering  rapidly,  and  giving  off  cirri ;  axial  canal  circular  at 
the  top  of  the  column,  but  pentalobate  farther  down. 

Distribution.  —  Only  known  from  the  Upper  Ilelderberg  group. 

Type  of  the  genus.  —  Iladrocn'mis  cUscks  Lyon. 

Ecinarls. — The  specimens  are  all  imperfect,  and  no  satisfactory  definition 
of  the  genus  can  be  given.  It  is  allied  to  Stcrcocriniis  in  having  but  one 
costal  to  the  ray,  but  differs  essentially  in  the  number  and  arrangement  of 
the  interbrachials,  and  in  having  .sometimes  an  anal  plate.  L3on's  descrip- 
tion of  the  column  needs  confirmation,  being  made  from  detached  pieces. 
His  JT.  jymtagomis  is  defined  from  a  single  ring  of  plates,  and  the  species 
cannot  be  recognized. 


"'(wmur-. 


Wt:  '■'-■  r^yfc«^7v  ;>»-*jiiWWl-*-'^ 


328 


THE  CRIXOIDKA  CAMERATA  OF  NORTH  AMERICA. 


Hadrocrinus  discus  Lvon. 
Plate  XXIV.,  Fiij.  1. 

isno.    Lyon  ;  Trans.  Amcr.  I'liilos.  Soc,  Vol.  Xlll.,  p.  MS,  Tlatc  26,  flg.  a. 
1S81.     W.  null  Sp.  j  Revision  I'lik'ocr.,  I'lirt  11.,  |).  Hi. 

A  very  large  species.  Dorsal  cup  flat-snucer-shnpcd,  tlie  rndials  forming 
a  sliallow  concavity,  of  which  the  basala  occupy  the  bottom,  the  radials  the 
sides.  From  the  top  of  the  radials  to  the  second  distichals  the  plates  are 
directed  horizontally,  and  from  there  they  proceed  slightly  upward  to  near 
the  arm  bases,  where  they  attain  again  a  horizontal  jiosition.  Plates  moder- 
ately heavy,  apparently  without  ornamentation;  slightly  concave,  the  median 
space  having  a  shallow  circular  pit,  sometimes  two  being  placed  clo.se  to- 
gether. Ba.sals  not  visible  in  the  specimens,  and  judging  from  the  space 
assigned  to  them,  they  were  unusually  small.  Radials  and  costals  small  ni 
proportion ;  the  former  a  little  the  larger,  their  lower  faces  one  half  the 
width  of  the  upper;  the  upper  sloping  faces  larger  than  the  corresponding 
lower  ones.  Second  costals  almost  regularly  pentagonal.  Distichals  2  X  10, 
larger  than  the  radials,  considerably  longer  than  wide ;  the  first  hexagonal, 
the  second  pentagonal  and  axillary.  Palmars  4  X  20  in  the  calyx,  the  two 
lower  ones  as  large  as  the  distichals  and  of  a  similar  form,  the  two  upper 
much  shorter  and  slightly  curved  for  the  reception  of  the  arms.  Inter- 
brachials  nine  or  more,  irregularly  arranged,  all  nearly  equal  and  as  large  as 
the  distichals.  The  anal  interradius  has  three  plates  in  the  second  row,  which 
are  narrower  than  the  two  of  the  other  sides.  Interdistichals  three,  longi- 
tudinally arranged,  elongate,  hexagonal,  as  large  as  adjoining  brachials. 
Structure  of  arms  and  ventral  disk  unknown.  Columnar  facet  large,  beauti- 
fully .striated. 

Horizon  and  Locality.  —  Upper  Helderberg  group ;  Falls  of  the  Ohio, 
near  Louisville,  Ky. 

Types  in  the  Lyon  collection. 

Hadrocrinus  plenissimus  Lvov. 
Plate  XXIV.,  Fi(js.  2a,  h. 

186!).     Lyon  ;  Tmn?.  Aiiier.  Pliil.is.  Soc,  Vol.  XIII.,  p.  Wa,  riak  20,  Figs,  i  1-3. 
18S1.     W.  nnd  Sp.  j  Revision  Pulii-ocr.,  Part  II.,  p.  222. 

The  specimens  are  fragmentary  and  crushed,  so  as  to  leave  some  doubt 
as  to  the  actual  form  and  size  of  the  calyx,  except  that  it  was  depressed  and 


J 


MELOCRINIDiE. 


329 


extrt'iuuly  large.  Lower  portions  of  the  dorMnl  cup  to  the  top  of  the  costnls 
deeply  concave,  forming  a  liirge  inverted  cup,  which  extends  deeply  into 
the  cavity  of  the  calyx ;  the  succeeding  plates  spreading  almost  horizontally 
with  a  slight  upward  curvature.  The  entire  surface  covered  with  somewhat 
flattened  ridges  passing  from  near  the  centre  of  the  plates  to  their  sides, 
where  they  meet  the  ridges  of  adjoining  plates.  There  are  from  two  to  four 
ridges  to  each  side,  but  two  of  them  are  frequently  united  in  the  specimens, 
so  as  to  form  one  larger  ridge  with  a  broader  surface. 

Basals  closely  united,  forming  a  small  inverted  cone,  which  occupies  the 
bottom  of  the  dor.sal  cavity  and  is  completely  hidden  by  the  column.  Tlio 
inner  or  ventral  surface  of  the  basals  is  convex,  decidedly  wider  than  the 
outer  or  dorsal  surface,  and  marked  by  five  well  defined  angular  ridges, 
radial  in  position,  from  which  small  protuberances  pass  out  and  enter  the 
axial  canal,  producing  the  j  italobate  outline.  Between  these  ridges  and 
around  the  axial  canal,  there  are  five  shallow  circular  depressions  occupying 
two  thirds  of  the  basnis,  which  probably  lodged  the  quinquelocular  or  dorsnl 
organ.  Radials  large,  somewhat  variable  in  size,  about  as  wide  as  long;  the 
lower  faces  wider  than  the  i,j)per ;  the  upper  sloping  faces  less  than  one  hidf 
the  length  of  the  lower  ones.  Costals  pentangular,  very  much  smaller  than 
the  radials,  sometimes  barely  one  third  their  size.  First  interbrachial  rising 
to  the  top  of  the  costals,  the  two  of  the  second  row  elongate  and  but  little 
smaller;  they  are  followed  by  other  rows,  but  their  arrangement,  as  well 
as  that  of  *\ie  higher  brachials,  cannot  be  accurately  determined  from  the 
specimens. 

Horizon  and  Locality.  —  Upper  Helderberg  group ;  near  Jeflersonville, 
Ind. 

Ti/pes  in  the  Lyon  collection. 

Remarls.  —  Lyon  describes  this  species  as  having  2X2"  secondary 
radials,"  and  several  more  "orders  of  radials"  above,  each  order  represented 
by  two  plates,  and  he  mentions  seven  to  eight  "  interradials  "  and  two  "  in- 
teraxillaries."  He  also  suggested  from  small  detached  pieces,  which  may 
possibly  belong  to  a  very  different  form,  that  this  species  hnd  from  eighty  to 
one  hundred  arms ;  all  of  which  has  yet  to  be  confirmed  by  more  perfect 
specimens. 


m 


T 


CALYPTOCRINID^. 

Monocyclic.  Lowku  bhachials  and  interuiiaciiials  foiimino  an  important  part 
OP  TUB  dorsal  cup.  Uadials  in  contact  all  around.  Arms  kestino  in 
compartments,  formed  uy  partitions  attacued  to  the  teumen.  Plates  of  the 
calyx  limited  to  a  definite  number.  Dorsal  cup,  except  the  base,  pekfectly 
pentamerous. 

AiKilytiis  of  the  Genera, 

Basal*  4. 

1.    Pnrtitlonsextendintjfothet'ipaoftheuvms El'CAi.YPTOCRlNrs. 

L'.   Puvtitiuna  enclusinij  (inly  the  lower  jioHiona  of  the  anus Callicuinus, 

GtolnijienI  and  (ieor/raphkal  Distribution. 
Number  of  known  species. 

(Open  figures  indicate  American  ;  those  marked  ( ),  European) 


FORMATIOX. 

CAI.TrTOCIllSID*. 

General. 

Aniericiui. 

ApiH'oxiinate 

Kuropoan 

Equivalents. 

Eucalyptocrinus. 

Callicrinus. 

Devonian. 

Eifel. 

U) 

Upper  Silurian. 

Niagara. 

Wenlock. 
Gotland. 

17     (10) 

4         (8) 

Total  species  40  |  ,jL 

n   (11) 

4         (S) 

Remarks.  —  Roemer  proposerl  the  family  name  "  Eucnlyptocrinida9  " 
(Lethoea  Geognos.  (Ausg.  3),  1855,  p.  229),  which  Angelin  in  1878  changed 
to  Calyptocrinidffi.  Tlie  latter  name  was  accepted  by  Zittel,  who  errone- 
ously included  with  it  Li/riocrimm^ViW,  which  is  a  dicyclic  Crinoid. 

The  Calyptocrinidne  agree  substantially  with  the  Dolatocrinites  .section  of 
the  Melocrinidae  in  the  construction  of  the  dorsal  cup,  but  their  basals  occupy 
the  bottom  of  a  deep  concavity,  and  they  are  remarkable  for  having  the 


iw 


[ 


CALYFrOCRINIDvE. 


881 


■ 


Fio.  15.  Fiti.  14.  Fio.  in. 

Fio.  II',  showing  plntcs  of  t]io  dorsiil  cup,  the  arms  and  their  partitions. 

Fio.  15,  the  cul;x  in  a  side  view. 

FlQ.  10,  llie  partition  walls  u(  KiiraU/ptocrinua  rosaeeus  (after  Sehiiltzc). 

i:=hasnls;  72  =:  Railials  ;  /=:costaIs;  //=(li!>ticlml9  ;  iir  ^  inlorhrachials  ;  iV  ^  intcrdisticlials 
/^  =  arnis;  (/•/'=  intcrradial  partitions;  iV//'=  intcnlistichal  partitions;  /i  :=  llrst  ring  of  plates  of  the 
trgnicn  ;  13  =  the  second  ring ;  (S  ^  the  third  ring  ;  and  /4  =  t\ie  fonrth  or  npper  ring  of  the  tcgnien, 

plates  imited  to  a  certain  number.  The  dorsal  cup  is  perfectly  pentamerous, 
the  rays  being  separated  by  intorbrnchialH  of  uniform  number  and  size,  and 
their  main  divisions  by  a  single  large  interdistichal.  Still  more  important 
from  a  classificatory  point  of  view  is  the  structure  of  the  ventral  di.^k,  which 
differs  from  that  of  any  other  known  Crinoid,  recent  or  fossil.  It  is  com- 
po.sed  of  only  four  rings  of  largo  plates  of  irregular  form,  of  which  the  two 
lower  ones  completely  cover  the  disk  ambulacra,  which  rre  subtegminal,  the 
upper  ones  forming  a  long  neck  or  tube  enclosing  a  narrow  canal.  Not 
only  do  the  plates  of  the  disk,  like  those  of  the  do".sal  cup,  consist  of  a  defi- 
nite number,  but  tliey  are  throughout  tliis  family  unusually  large,  and  their 
arrangement  does  not  appear  to  be  in  accordance  with  the  pentamerous 


88a 


THK  t'KINOlDKA  CAMKIIATA  OF  NOttTII   AJIKIIK'A. 


Hyinmotry  of  tliu  Crinoiils  generully.  Aiiotlicr  most  rctnnrknhio  feature, 
wliieli  MupiiiatuM  tliiis  family  diHtinctly  from  all  other  Ciimuratii,  is  tlie  coiii- 
partiiU'UtM  eiicioHing  the  aniis,  which  tire  formed  by  processes  or  imrtitioiis 
attached  to  the  outer  si''"  of  the  disk,  and  uro  supported  by  the  iiiter- 
brachials  and  interdistichals. 

The  family  was  restricted  to  the  Upper  Silurian,  with  the  exception  of 
a  single  species  found  in  the  lower  Dovonian  of  the  Kifel.  It  was  the  lead- 
ing family  '  f  its  epoch  in  the  number  of  species  discovereil,  there  being 
twenty-one  from  America,  and  eighteen  from  England  and  Sweden,  but  only- 
two  genera. 

EUCALYPTOCRINUS  (ioiDK. 

1820.    Goi.Dfims;  I'etrcf.  (ii'iniiin.,  Vol.  I  ,  p.  iU,  mid  183S,  Nova  AoU  Leop.  Vol.  XIX.,  1,  p.  335. 

bll.     MOli.kii;  Ui'il.  Akiid.  <l.  Wi.xsciiscli.,  p.  210. 

18  U.     ll.ALi,  i  I'liliiMmt.  N.  York,  Vol.  II.,  p.  -207. 

13W.     ItoKMKiij  Klii'in.  Url)cr)?iiiigs),'rl) ,  p.  (i'J,  iiiiil  1855,  Lctlmctt  Oeogn.  (Ausg.  3),  p.  257,  nnd  1800, 

Silur.  Fiiuim  Wrst.  'IVini.,  p.  48. 
1853.     lie.  K()Ni.N(  K  ami  I.kiion  ;  Ucclicr.  sur  les  Criiioides  du  Terr.  Carboiiifcrc  de  la  Bflgiiiut,  p.  7h  willi 

diiigriiiii. 
1857.     Pktet;  Truilu  ile  I'alcoiitologie,  Vol.  IV.,  p.  307. 
1^0:2.     DnjAKUi.N  mid  Hii'K;  Hist.  Nut.  des  Zoopli.  Deliiii.,  p.  115. 
180:!.     H.\l.[.i  Trails.  Albany  Inst.,  Vol.  IV.,  ji.  li)7. 
18iill.     Sl'iiultzk;  Monogr.  Kcliiii.  Kill.  Kidk.,  p.  UO. 
1S7'<.     AxoKLl.v;  leonnpr.  Crin.  Slice,  p.  10. 

187'J.     I1.VU.;  28tli  \U-\).  New  York  Slate  .\liis.  Nat.  Hist.,  (Kd.  II  ),  p.  141. 
1879.     ZiTTKi,;  llandb.  dcr  ralii'ontolosii',  Vol.  I,  p.  370. 
1885.     QiKx.sTKDT ;  Haiidl).  d.  IVtrcfactrnkniide  lAiisg.  3),  ]>.  "JfiS. 

1S8J.     W.  and  Sp. :  Kevision  I'alii'ocr.,  Part  III.,  p.  127  i  I'locced.  Acad.  Nnt.  8ci.  Pliila.,  p.  349). 
18S9.     S.  A.  .Mii.i,Kii;  N.  AiiiiT.  (ii'ol.  and  I'alii-ont.,  p.  2 Hi. 

Sp\.  J/i//Mii/iocri/ii4.i  I'liii.Lirs,  ls:!9;  Miiicliisuii's  Sdur.  System,  p.  072,  I'latc  17,  i'ig.  3 ;  ZittuI, 

1879  J  Angelin,  1878  j  S.  A.  Miller,  18S0. 

Calyx  with  the  arms  attached  more  or  less  ovate ;  without  the  arms 
resembling  a  wine  bottle  with  concave  bottom  and  slender  neck ;  the  neck 
surrounded  by  ten  longitudinal  partitions  closed  from  above,  and  forming 
ten  niches  or  compartments  into  which  the  arms,  in  pairs,  and  to  their  full 
length,  exactly  fit.  Dorsal  cup  composed  of  four  bnsals,  five  radials,  2X5 
costals,  2x10  distichals,  1  X  20  palmars,  3X5  interbrachials,  and  1X5  inter- 
distichals. The  basals,  which  form  an  inverted  funnel-shnped  cup,  are  not 
visible  from  a  side  view,  and  the  calyx  rests  upon  the  edges  of  the  inflected 
lower  portions  of  the  radials;  the  plates  varying  in  size,  the  anterior  one 
larger  than  the  rest.  Axiid  canal  five-rayed,  the  anterior  basal  pierced  by 
two  of  its  rays.  First  costals  quadrangular,  the  second  pentangular  unless 
the  upper  angle  is  truncated  by  the  interdistichal.     First  distichals  larger 


41^ 


i!i 


(■•!< 


CALYlTOf  RlNIDiK. 


833 


^1^ 


1 


than  the  Kccotid.  The  firnt  piilinarH  Hiipport  the  nrniH;  thoy  are  whort,  trun- 
cated at  the  upper  face,  and  are  provided  with  Huiall  niiiwit'  jjlntes  and 
fo8.sto.  Fir.>*t  interbracliialM  generally  the  largest  i)lateH  ol'  the  dornal  cup, 
more  (hiui  twice  an  large  a«  the  two  above.  The  two  latter  are  of  about  the 
same  form  and  nize,  and  are  in  contact  laterally  to  their  full  length.  Tiiey 
rine  womo  distance  beyond  the  top  ol'  the  palniars  in  scjuare  or  tapering  trun- 
cate projections,  and  jointly  form  a  support  lor  the  interradial  partitions. 
The  interdistichab  rest  either  within  notches  formed  by  tiio  distiehals,  or 
upon  the  trinicato  upper  face  of  the  second  costals.  They  resendde  in  form 
the  combined  upper  intorbrachial.s,  rise  like  these  to  the  height  of  the  third 
arm  plates^  and  support  in  a  similar  maimer  to  the  interbrachials  a  partition 
woU  npon  their  truncate  upper  faces.  The  projections  between  the  arm 
sockets  give  to  the  specimens  a  very  nnirked  aspect,  and  serve  as  a  reliable 
guide  for  generic  identification  in  case  the  ventral  structures  of  the  calyx 
are  not  preserved  ;  in  that  condition  they  look  like  cogs  of  a  wheel. 

The  toginen,  or  part  above  the  dorsal  cup,  consists  of  four  rings  of  plates 
of  peculiar  structure.  The  lower  ring  is  composed  of  five  elongate  inter- 
radial pieces  which  rest  npon  the  i)rojecting  upper  faces  of  the  interbrachials, 
and  five  plates  of  similar  form  and  size  supported  by  the  interdistiehals. 
The  middle  portions  of  the  ten  plates  extend  outward  and  upward  in  form  of 
knife-like  winged  proces,ses,  of  which  the  upper  end  rises  to  near  the  fourth 
row  of  plates,  overlapping  the  plates  of  the  second  and  third  rows,  to  the 
outer  faces  of  which  they  are  attached  by  suture.  Interposed  between  thefe 
plates  are  ten  small  trigonal  pieces,  arranged  in  such  a  manner  that  a  plate 
supported  by  an  interbrachial,  and  one  supported  by  an  interdistichal,  always 
meet  laterally  over  the  top  of  one  of  the  triangular  pieces.  The  latter  plates, 
which  are  somewhat  thickened  at  their  median  lines,  form  a  .sort  of  subpar- 
titions between  the  arms  of  the  various  pairs,  without  being  visible  when  the 
arms  are  intact.  Their  e<lge8  at  both  sides,  and  also  tho.se  of  the  larger 
plates,  are  pierced  by  the  ambulacral  or  arm  openings,  which  are  well 
defined  in  this  genus,  and  enter  the  calyx  between  the  two  plates.  The 
second  and  third  rings,  which  form  the  tubular  prolongation  of  the  calyx, 
are  composed  of  four  plates  eacli ;  the  fourth  ring  consists  of  ten  pieces, 
which  meet  around  the  summit.  The  plates  of  the  second  ring  slope 
upwards ;  two  of  them  are  wider,  and  alternate  with  the  other  two ;  the 
two  narrower  plates  are  longer,  and  angular  at  the  top,  the  others  truncate. 
United  they  form  an  inverted  funnel,  the  margin  surrounded  by  ten  protu- 


1-  i 


834 


TIIK  (  UIN<HI)KA   CAMKUATA  OF   NOUTII    AMKHK  A. 


boraiiooH,  wliicli  represent  ton  lonKihuliniil  ridgen  upon  the  outer  Rurfacc. 
Tlio  riilgeN  meet  tlio  upwiird  pmluiigationM  uf  the  platen  of  the  firat  ring, 
with  which  they  are  HUturally  cuuueeted  and  tbrni  a  nolid  wall ;  while  the 
alternate  groovcM  form  the  inner  ,iart  of  the  Jiirlien.  The  platoM  of  the  third 
ring  are  narrower  than  those  of  the  xocond,  and  like  them  provided  with  ten 
longitudinal  clevationi^,  which  are  overlapped  hy  certain  projeetioUH  paHHing 
down  from  the  platoH  of  the  fourtli  ring.  The  platoH  of  the  upper  ring  are 
quite  remarkal)lo  as  forming  the  upper  part  of  the  anal  tid)e,  the  top  of  the 
crown,  and  at  the  «ttme  time  the  encasement  for  the  tips  of  the  arniH.  They 
are  constructed  upon  a  plan  similar  to  that  of  the  large  plates  of  the  first 
ring,  and,  like  them,  have  wing  like  extensions,  which  from  a  ventral  aspect 
present  a  well  tlefined  decagonal  star,  with  n  vacant  space  at  the  Nummit. 
The  lower  ends  of  these  wings  meet  the  upper  ends  of  the  wings  rf  the  first 
ring,  HO  as  to  form,  together  with  the  projecting  surfaces  upon  the  plates  of 
the  two  middle  rings,  ten  continuous  walls,  which  extend  from  the  edges  of 
the  dorsal  cup  to  the  top  of  the  crown.  The  open  space  between  them 
represents  the  end  of  the  anal  canal,  which  is  closed  variously  by  from  five 
to  ten  small  irregular  pieces  surrounding  tiie  anal  opening,  and  sometimes  by 
additional  larger  plates.  The  anus  in  i-omo  species  is  drawn  out  to  a  tube 
of  great  length,  extending  far  beyond  the  limits  of  the  arms,  but  more  fre- 
quently rises  but  little  above  the  top  of  the  compartments.  Arms  heavy, 
arranged  in  pairs,  each  pair  occupying  one  of  the  ten  compartments,  their 
backs  almost  even  with  the  edges  of  the  partitions,  their  lateral  faces  abut- 
ting against  the  sides.  They  have  a  wide  ventral  furrow,  and  are  composed 
from  the  third  or  fourth  plate  tip  of  two  rows  of  short,  transverse  pieces, 
which  are  .so  closely  united  l>y  suture,  that  the  arms  must  have  moved  cii 
masse  upon  the  calyx.  Pinnules  long  and  closely  folded.  The  visceral 
cavity  is  formed  by  the  plates  of  the  dorsal  cup  and  the  two  lower  rings  of 
plates  of  the  disk  ;  the  plates  of  the  two  upper  rings,  whicli  form  the  neck- 
like prolongation,  being,  properly  speaking,  plates  of  the  anal  tube.  The 
ambulacra,  on  entering  the  calyx,  follow  the  grooves  at  the  inner  floor,  and 
meet  near  the  top  of  the  second  ring.  Column  moderately  large,  generally 
round  ;  composed  of  rather  long  joints  with  pentapetalons  axin!  canal.  It 
has  no  lateral  cirri,  but  branches  at  the  end  into  hundreds  of  little  rootlets. 

Dlstrihut'inn.  —  A  leading  form  of  the  Upper  Silurian,  and  well  repre- 
sented in  this  country  as  well  as  in  Europe.  A  .single  species  is  known  from 
the  Devonian :  Encalyptomnus  rosaceiis  from  the  Eifel  of  Germany,  the  t^pe 
of  the  genus. 


CALYlTOdUMDvE. 


335 


lifmurkH.  —  Kitidlt/pforriniix  wiih  oriH:iniiny  doncrihcd  Uy  CJoldfiiMK  iin  lniv- 
iiig  iiu  HtuiM  ;  and  I'liiltiim,  wliu  diHcuvurud  iiiiutliur  HpucivM  with  tliu  Mtum 
iittiiclicd,  pi'U|io.<«fd  fur  tliiM  tliu  guiiiiH  //i/pitnthorriniin.  Aii^^cliii  mid  /itttil, 
who  iiciu'|)tcd  IMiillipK'  gomiM,  doMCiihi-  itn  hiixo  iih  Iukm  det'iily  rntiiud-NhaiH'd, 
thu  aiiiil  tubu  art  cxtoiidiii}^  boyuiid  the  tip.<i  of  thu  uiiiih,  and  tlii!  partition 
walls  uiicloHing  thu  ariiiH  aH  huiiig  coiiNtriictud  principally  of  unu  |)iuco. 
Nuithur  onu  ofthoHo  I'hariicti'rH  Im  cotiMtaiit,  and  wo  c-aniiot  regard  (hu  two 
furinM  aH  diutinet  gunuriually.  That  tliu  anal  ttibu  riMus  ahovu  the  iiriiiM  Im  uf 
vury  litlli*  Htriictnral  value,  if  wu  admit  that  thu  iiuck-liku  prolongation 
troin  tlio  disk  rupreMuiit«  ii  part  of  that  tiibo.  Tho  earlier  writern  deMcriho 
tlio  riulials  ns  haMaU.  Iloeinur  diftcovcrud  tho  true  baHo  in  1H4!},  but  ho 
HuppoHud  it  waH  quini|iiu-partito,  and  mo  did  do  Kuninok  and  fje  Hon.  Mall  in 
1S03  found  that  it  cotiHiHtcd  of  but  four  plates,  and  tluH  wkh  contirnicd  by 
Hubsefjiiunt  authors. 

Knriih/jitiirrliuis  is  a  most  porjloxing  goniiH,  owing  to  tho  peculiar  xtriic- 
tiiro  of  its  v(  itral  ]i)i>rt,  which  v  as  apparently  not  correctly  understood  by 
Hall.  lie  de^-;ribed  the  partition  walls  as  interbrachialH;  while  in  fact  they  are 
not  separate  plates,  but  tho  outer  proccxses  from  tho  plates  of  tho  disk  and 
tube,  respectively,  a  sort  of  compound  structure  for  which, we  adopt  the  name 
'•partition  walls."  The  uventy  pi.  ,  m  fonmng  tho  lower  ring  of  the  disk  we 
regard  as  largo  interambulacrni  p'  's  meeting  over  the  ambulacra ;  but  as 
to  the  relations  of  the  plates  ol  t!io  .-ocond  ring  we  are  somewhat  in  doubt. 
Wo  have  suggested  in  Il.Msion,  Part  III.;  .-.  132,  that  they  probably  repre- 
sented four  of  the  or  is,  a.'  '  that  the  fifth  was  pushed  upward,  and  consti- 
tutes a  part  of  the  anal  tube.  This  seems  not  impro-  iM  »  if  we  consider  that 
the  posterior  oral  in  all  Palmozoic  Crinoids  is  puslic.  more  or  less  out  of 
place  by  the  anus ;  and  it  may  bo  expected  that  this  was  tho  case  to  a  high 
degree  in  a  genus  in  which  the  anal  tube  is  lorgo  and  strictly  central. 

Miller's  Ei(c(tliip(orrinus  elli/i(iriis  is  too  young  a  specimen  to  determine  its 
specific  relations.  A  similar  specimen  from  Rochester,  N.  Y.,  is  figured  by  us 
on  Plato  LXXXIII.,  Fig.  7. 

Eucah/ptucrinns  tmncusew,  E.  rhilUpni,  E.  conicus,  E.  nnnhfilJa,  E,  aiensus, 
E.  gibhoms,  E.  Iceris,  nnd  E.  Goldfiissi,  all  of  Troost,  are  mere  catalogue  names. 
E.  arw".'!'  ••  McChesney  is  a  Si/ihniiocriims,  and  E.  cormitun,  E.  crmvaius, 
both  desoiibed  by  Hall,  and  E.  rami/er  of  Eoemer,  have  been  referred  by  us 
to  CalUcnnus. 


'^-^rmir . 


• 


330  TIIK   CUINOIDEA   CAMERATA   OF   NORTH   AMERICA. 

Euoalyptoorinus  coelatus  (Haix). 
Plate  LXXXin.  Fhjx.  5,  0,  7. 

1843.    Geol.  Rep.  4tli  Distr.  N.  York,  p.  113,  Fig.  1,  niiil  I'liln-init.  N.  Y.,  p.  ilO,  I'lntc-  17,  Figs,  4ff,  b,  e,  <i. 
1885.     W.  mill  Sp.  (ill  |)art)  ;  IlcviMii)ii  I'iiIiviht.,  I'lirl  III.,  p.  1.1.''. 

Not  Eiiciili/iilocnMiin  err/alun  Hall,  18()."),  Tniiis,  Allinny  lust.,  p.  C?<i  (Abslr.,  p.  38),  and  SOlli  Krp. 

N.  Y.  M.ilc  Ciil).  Nftt.  Hist  ,  pp.  341   t(i  3:!'.)  (soeoml  rd.,  pp.  3f.;t-3(>+),  mid  iiStli  Hep.,  p.  142, 

riiilo  IC),  Fif,'s.  1-10,  mill  riute  11),  V\\;a.  1-3;   iiUo  lllli  Ann.  Oral.  Hep.  liiilinim,  p.  274,  Pliite 

l.'i,  V'\K.  1,  i'latc  10,  Figs.  1-10,  I'lntc  19,  Figs.  1-3,  iilt  of  wliicli  wc  refer  to  EucalfptoeriHW 

KImli  S.  A.  Miller. 
Nor  Knciiljf/>/ucriiiua  ctr/dlHt  RoEMKH ;  Siliir.   Fniiim  West.  Tciiii.,  p.  48,  Pliite  4,  Figs.  .'J(i-c=: 

E.  vnittif'uxitx. 
S;n  (?)  Kucnlifptnrriiius  {IIifimHthorriiiiis)  ilenriix  Hall,  \'^\fi  (not  Miiroliison,  1S39)  ;  Geol.  Hep. 

4lli  Distr.  N.  York,  p.  113,  Figs.  ?-3,  mid  1S52,  I'lilwonl.  N.  York,  Vol.  II.,  p.  207,  Plate  47, 

Figs.  1-3,  mid  Plate  8.5,  Fig.  7. 
Syn.  Kuealj/plocriiiun pttpHlosHs  Hall;  I'lilieont.  N.  York,  Vol.  II.,  p.  211,  Plate  47,  Figs.  5a,  b. 

or  medium  size.  Length  of  crown  compared  with  the  grcnteat  widtli  at 
the  arm  bases  as  3  to  1,  and  witli  the  height  of  the  dorsal  cup  as  3  to  2. 
The  Clip  subturbinate,  uniformly  spreading  from  the  middle  of  the  radials  to 
the  arm  bases,  the  bottom  part  somewhat  rounded.  The  plates  of  the  cup 
densely  crowded  with  small  pustules  of  uniform  size,  and  similar  pustules,  or 
small  nodes,  cover  the  outer  edges  of  the  partition  walls  to  half  their  height ; 
the  upper  part  being  marked  by  indistinct  transverse  ridges. 

Basal  concavity  small,  completely  filled  by  the  upper  part  of  the  column. 
Radials  large,  wider  than  long,  very  slightly  inflected,  their  lower  ends  thi'-k- 
ened  by  a  round,  wart-like  projection,  which  is  devoid  of  ornamentation  ;  the 
sloping  upper  faces  short;  the  upper  face  concave.  First  costals  wider  tiian 
long,  the  sides  all  convex,  the  upper  face  narrower  than  the  lower.  Second 
costiils  the  size  of  the  first,  but  pentangular.  First  distichals  smaller  than 
the  costals ;  the  second  smaller  than  the  first.  Plates  supporting  the  arms 
small  and  irregularly  qiiadrangidar.  First  iuterbrachial  very  large,  longer 
than  wide,  and  tapering  downward  ;  the  two  succeeding  ones  together  almost 
as  large  as  the  first ;  they  rise  to  a  level  with  the  third  arm  joints,  are  wider 
at  the  bottom  than  at  the  top,  and  unite  by  a  vertical  suture.  The  interdis- 
tichals  rarely  touch  the  axill.iry  costals  ;  thov  are  twice  ns  long  as  wide,  and 
one  third  narrower  tlian  both  upper  interlirachiids  together.  Partition  walls 
almost  as  thick  at  the  upper  end  as  at  the  lower,  and  distinctly  rounded  on 
the  back.  Arms  tapering  upward  to  fully  one  half  their  greatest  width. 
The  four  proximal  arm  plates  single  and  somewhat  longer  than  the  others ; 
the  two  succeeding  ones  cuneate,  and  those  above  arranged  in  two  series, 
which  deeply  interlock.    The  aims  are  covered  with  transverse  rows  of  elon- 


^ 


CALYPTOCRINID^E. 


337 


^ 


gate  nodes.  Anus  at  llie  end  of  a  small  tube,  rising  4  to  5  mm.  above  the 
tips  of  the  arms.  Ventral  part  of  the  calyx  not  visible  In  any  of  tiie  speci- 
mens. Column  round,  the  nodal  joints  very  long  and  rounded  at  the  outer 
margins,  the  younger  joints  short  and  narrow. 

IlorUon  and  Localiti/.  —  Niagara  group  ;  Lockport  and  Rochester,  N.  Y. 

Tifpc  specimen  in  American  Museum  of  Natural  History,  New  York. 

lientarh.  —  It  is  probable  that  the  specimens  which  Hall  referred  to 
Eiirah//>/ocrintis  dironts  Phillips,  arc  identical  with  this  species.  They  cer- 
tainly differ  es.sentially  from  the  English  species  (Plate  LXXXII.,  Fig.  15), 
which  is  proportionally  shorter  and  stouter,  the  plates  heavier  and  more  con- 
vex, the  partition  walls  thinner,  the  anal  tube  stronger,  and  the  column 
obscurely  pentangular  instead  of  round. 

The  Waldron  specimens  with  ornamented  plates,  which  Hall  identified 
with  this  species,  have  been  referred  by  us  to  Euml/jptocrinus  Elrodi  Miller. 

Euoalyptocrinus  tuberoulatus  Millku  axi>  Dvku. 
Plate  LXXXIII.  Figs.  8,  .9, 10. 

1878.     MilXEHBiid  Dvkb;  Joiim.  Cinciii.  Soc.  Nnt.  Hist.,  Vol.  I.,  p.  3fi,  I'liitc  2,  Figs.  9,  9(7. 
1885.     W.  1111(1  Si'. ;   Kevi.sidii  I'lilimcr.,  I'mt  III.,  p.  I'M. 

Svn.  Eiiriilyitlorriiim  miirulis  KiNofEiiEiKi  ;   IS'JO,  .\111ml3  N.  Y.  Acad.  Sei.,  Vol.  V.,  ]>.  305,  Plate 
3,  Fig.  3. 

In  its  general  form  rcsemltling  the  preceding  species,  but  diflfering  some- 
what in  the  proportions  of  the  plates.  Dorsal  cup  obconical,  nearly  as  high 
as  wide,  sides  slightly  convex,  the  lower  end  moderately  truncated.  Plates 
a  little  elevated  and  covered  by  numerous  tubercles  of  various  size,  larger 
ones  being  interspersed  between  smaller  ones;  the  suture  lines  distinctly 
grooved.  Columnar  concavity  narrow,  its  depth  less  than  the  width  ;  the 
ba.sals  completely  covered  by  the  upper  end  of  the  column. 

Radiiils  considerably  longer  than  wide,  rapidly  tapering  downward, 
rounded  at  tiie  bottom ;  the  lower  end  inflected  to  meet  the  bii,«als ;  the 
lower  face  very  narrow,  equal  to  one  third  the  width  of  the  upper,  which  is 
rather  deeply  concave  ;  the  sloping  upper  fares  short.  First  costtds  longer 
than  wide,  narrowest  at  the  upper  end.  Second  costals  wider  than  the  first, 
pentangular  or  hexangular.  First  distichals  from  one  third  to  one  half 
smaller  than  the  costals ;  the  second  barely  one  third  the  size  of  the  first ; 
the  arm-bearing  palmars  very  much  smaller  and  triangular.  First  inter- 
brachials  elongate,  once  and  a  half  as  long  as  wide,  and  nearly  as  large 

43 


•''^"VUfm.ir 


I 

i 


338 


TIIK  CRINOIDEA  CAiMERATA  OF  NORTH  AMERICA. 


. 


as  the  liidiiils;  thuy  are  widest  next  to  tlie  intercostal  sutures,  tapering  to 
both  ends ;  the  lower  lateral  faces  convex,  and  longer  than  any  of  the 
others;  the  upper  faces  meeting  the  interbracliials  of  the  second  order.  The 
two  latter  plates  combined  are  but  little  smaller  than  the  lower  one,  their 
tips  rising  conspicuously  above  the  arm  facets,  and  very  little  truncated. 
Interdistichals  much  smaller  than  the  corresponding  interbracliials,  their 
lower  ends  touching  the  costals  or  resting  between  the  upper  sloping 
faces  of  the  distichals.  The  remaining  parts  of  the  species  are  not  shown 
in  the  specimens,  but  it  may  be  suggested  from  the  condition  of  the  inter- 
bracliials and  interdistichals  that  the  partition  walls  were  unusually  thin. 

llorizun  and  Lwality.  —  Niagara  group ;  Waldron  and  Ilartsville,  Ind., 
Lockport,  N.  Y.,  and  Racine,  Wis. 

Tijpcs  in  the  Museum  of  Comparative  Zoology. 

Jii'iu((r/,-s.  —  Miller  and  Dyer,  in  their  specific  description,  after  giving 
the  structure  of  the  brachials,  and  stating  that  the  first  interbracliials  are 
"  nine  or  ten-sided,"  continue  as  follows :  "  This  description  applies  to  the 
two  ton-sided  interradials;  the  other  three  have  only  nine  sides,  as  shown 
by  Plate  2,  Fig.  9,  and  differ  in  supporting  one  supraradial  instead  of  two." 
Even  if  this  were  true,  which  is  not  the  ca.se,  it  would  have  no  specific  sig- 
nificance, but  would  only  indicate  an  abnormal  condition  of  that  specimen. 
By  giving  the  specimen  some  additional  cleaning,  wo  disclosed  two  distichals 
in  every  ray,  all  supporting  two  extremely  small  pahnars,  as  shown  by  our 
figure  (Plate  LXXXIII.,  Fig.  0).  The  peculiarity  that  some  of  the  inter- 
bracliials are  nine-sided,  is  caused  by  the  distichals,  which  in  three  of  the 
rays  loan  over  to  one  side,  so  that  one  of  them  docs  not  touch  the  intorbrnch- 
ials.  In  Miller  and  Dyer's  second  type.  Fig.  On  on  the  same  plate,  which 
wc  also  reproduce  (Plate  LXXXIII.,  Fig.  8),  the  respective  plates  are  all 
ten-sided. 

We  must  regard  Ewahipincrlnns  viurah's  Ringucborg  as  specifically  iden- 
tical with  E.  tiihircu/atits,  until  better  specimens  are  found.  Of  Ringiub(Mg'.s 
type,  which  we  had  for  comparison,  only  the  dorsal  cup  is  preserved,  ami  this 
is  so  badly  crushed  as  to  give  no  idea  of  its  actual  form.  It  is  quite  possible 
that  the  base  is  somewhat  broader  than  in  Miller  and  Dyer's  types,  that  the 
plates  generally  are  a  little  more  convex,  and  the  tubercles  upon  the  plates 
somewhat  less  proniinont.  but  the  proportions  of  the  plates  are  substantially 
the  same.     Shnilar  \  ariations  may  be  expected  in  the  limits  of  any  species. 


i 


CALYITOCRINIDvE. 


339 


Euoalyptoorinus  Elrodi  s.  a.  ^Iiller. 

(Revised  W.  and  Sr.). 
Plate  LXXXI.  Fuja.  7a,  b,  8,  9, 10, 11, 12, 13. 

ISOl.    S.  A.  Mti.i.Rn;   Ad.  Sheets  17lli  Kep.  Geol.  Surv.  ludinim,  p.  40,  I'late  7,  Figs.  9,  10. 

%pi.  Eiiiiili/ptoeriiiiis  enlalut  Hali,,    ISCa  (not   ISi;!)  I   Trans.  All).  Insl.,  p.  2i()  (Abstr.,  p.  32) ; 

iiiiil  (r)  ;iOtli  Uep.  N.  Y.  Stale  Cal).  Niil.  lli>t.,  y.  ;W1  (ivvisctl  cililion,  p.  'MYA),  and  2Stli  Ucp., 

p.  142,  riiile  10,  Fifjs.  1-10,  and  I'lal.'  19,  Fi(,'s.  1-3;  al.so  lllli  Ann.  Geol.  Kcii.  Indiana,  p.  271, 

IMalc  10,  r    ,.  1-10,  and  I'lalc  19,  Figs.  1-:!. 
Sjn.  Eurul^iilwriiim  subi/totuaua  S.  A.  .M1LI.EB,  1S91,  Adv.  Sliects  17lli  Kop.  Geol.  Shft.  Ind.,  p.  ;i7, 

Pinto  7,  1 ig  3. 

Usually  a  little  larger  than  E.  cwlatus,  Hhorter  in  proportion,  and  not 
attenuate  at  the  poles.  General  form  from  subglobose  to  ovate,  the  base 
inoilenitoly  excavated  for  the  reception  of  the  column.  Dor-al  cup  a  little 
shorter  than  the  height  of  the  partition  walls  enclosing  the  arms.  The 
plates  of  the  dorsal  cup,  a.s  well  as  the  arms,  and  also  the  outer  edges  of  the 
partition  walls,  marked  by  numerous  round  or  elongate  nodes,  often  two  or 
three  of  them  conlluent  and  forming  straight  or  vermicidar  ridges  trans- 
verse!}'  or  longitudinally  arranged.  The  nodes  upon  the  arms  are  in  longi- ' 
tudinal  rows,  there  being  generally  two  rows  in  the  upper  part  of  the  arms, 
and  four  at  the  lower  end. 

Basal  concavity  small  and  shallow  for  the  genus,  the  plates  completely 
hidden  by  the  column,  forming  a  short  cone  at  the  inner  floor.  Radials  mod- 
erately large,  the  lower  ends  curving  abruptly  inward,  the  remaining  parts 
outward  and  slightly  upward,  the  lateral  faces  rapidly  tapering,  the  sloping 
upper  faces  short,  and  the  upper  face  concave.  First  costals  wider  than  long, 
the  sides  convex  ;  the  second  hexagonal,  the  upper  angle  truncated  by  the 
interdistichals.  First  distichals  once  and  a  Iialf  as  large  as  the  second,  and 
the  latter  more  than  twice  as  large  as  the  fixed  palmars,  which  are  subtri- 
gonal.  First  interbrachial  very  large,  the  middle  part  almost  as  wide  as  long, 
the  upper  end  broadly  trimcated  by  the  interbrachials  of  the  second  row- 
The  two  latter  plates  together  are  longer  than  wide,  having  the  greatest 
width  at  one  third  their  height,  whence  they  gradually  .slant  to  the  top, 
which  is  truncate.  The  interdistichals  are  of  a  similar  form,  but  one  third 
smaller  than  the  two  upper  interbrachials,  and  rise,  like  them,  considerably 
above  the  level  of  the  arm  bases,  each  supporting  also  a  partition.  The 
outer  faces  of  the  partitions  are  fully  twice  as  wide  at  the  lower  end  as  at  the 
upper,  and  are  slightly  grooved.     Arms  gradually  tapering  upwards,  quite 


340 


THE  CRINOIDEA  CAMERATA  OF  NORTH  AMERICA. 


f  ! 


narrow  at  the  extreniitioH,  composed  of  very  short  pieces ;  the  three  or  four 
proxinml  onea  simple,  the  upper  riitiier  deeply  interlocking.  Ventral  disii 
minua  tlie  partitions  comparatively  high,  owing  to  the  plates  of  the  fust  row 
which  are  unusually  large ;  the  plates  of  the  second  row  are  shallow  funnel- 
shaped,  and  those  of  the  third  shorter  and  very  heavy.  The  plates  of  the 
fourth  row,  which  form  the  npper  end  of  the  tube,  as  well  as  of  the  com- 
partments, enclose  six  or  eight  moderately  large  plates,  and  these  again 
a  little  short  cone  of  eight  or  ten  irregular  pieces,  which  decrease  in  size 
inward,  and  close  the  anus  more  or  less  tightly. 

IlorUon  and  Locality.  —  Niagara  group;  Waldron  and  Ilartsville,  Ind., 
and  Chicago,  Ills. 

TyjKs  in  the  State  Cabinet  of  Natural  History  at  Albany. 

Jicviarfis.  —  The  name  Eucali/plocrinus  Elrudi  was  proposed  by  Miller  for 
a  specimen  from  Ilartsville,  Ind.,  in  which  the  nodes  upon  the  surface  are 
exceedingly  regular,  and  not  in  part  confluent  as  usually  in  this  species, 
agreeing  in  other  respects  with  the  specimens  from  Waldron,  which  Hall 
erroneously  referred  to  E.  ccelatits.  The  latter  species,  as  represented  at 
Lock  port  and  Rociiester,  N.  Y.,  its  typical  localities,  is  much  more  elongate 
than  the  specimens  from  Indiana ;  the  dorsal  cup  is  higher  and  obconical,  the 
radials  longer  and  more  nodose  at  the  lower  end,  the  partition  walls  thinner, 
their  outer  edges  convex  instead  of  concave,  and  there  is  a  small  tube  rising 
above  the  walls  of  the  compartments.  Whether  imder  these  circumstances 
it  is  propc ;  to  accept  for  the  typical  form  Miller's  name  E.  Elrodi,  which  he 
separated  from  it  on  account  of  slight  modifications  in  the  ornamentation, 
may  be  questioned  ;  but  we  propo.se  to  do  so  to  avoid  further  synouomy. 
We  therefore  include  in  this  species  not  only  Miller's  special  form,  but  also 
the  specimens  from  Waldron  and  Ilartsville,  figured  by  Hall  under  E.  cwla/iis, 
and  also  Miller's  E.  sithf/Io/Mnus,  which  latter  we  regard  an  immature  form 
of  this  species. 

Euoalyptoorinus  omatus  Hall. 
Plate  LXXXII.  Fig.  10. 

1807.     Hall;  20lh  Rep.  N.  Y.  Stole  Cab.  Niit.  Hist.,  p.  329,  Pliite  11,  Figs.  4  ami  5. 
1S85.     W.  ii!id  Sp.  ;  Revision  I'iilicocr.,  I'art  HI.,  p.  134. 

The  dorsal  cup,  the  only  part  known  of  this  species,  was  descril)ed  from 
internal  casts  and  gutta  percha  impressions,  taken  in  the  natural  moidd  of 
the  exterior.     It  is  depressed,  as  wide  as  high,  the  radials  directed  hori- 


CALYFrOCRIMIXE. 


341 


zontnlly,  except  their  extreme  lower  ends,  wliieh  take  part  in  the  basal 
concavity.  CostaLs,  first  distichals  and  first  inturbrachials  curving  rapidly 
upwards,  so  that  tlie  sides  near  the  top  of  the  cup  are  parallel  with  corre- 
sponding parts  of  the  opposite  side.  Surface  of  plates,  as  shown  from  the 
gutta  percha  impressions,  beautifidly  ornamented  with  elongate  nodes  or 
riilges  pa.ssing  out  from  the  centres  of  the  plates  to  their  sides,  but  not  con- 
tinued to  adjoining  plates. 

Basal  concavity  narrow,  and  moderately  deep.  The  radials  rapiilly 
tapering  to  their  lower  ends  and  rather  small,  not  larger  than  the  second 
costals,  which  are  considerably  larger  than  the  first.  Fir.xt  costals  (piad- 
rangular,  once  and  a  half  as  wide  as  long ;  the  second  hexagonal,  being 
truncated  at  the  upper  end.  First  distichals  about  a  third  smaller  than  the 
upper  costals ;  the  second  quite  small  and  the  palmars  still  smaller.  First 
interbrachial  larger  than  the  radials,  almost  as  wide  as  hijjh,  those  of  tiie 
second  row  together  smaller  than  the  first ;  the  interdistichul  sub-rhomboidal, 
the  upper  and  lower  angles  truncated, 

Ilurhon  and  Lomlltij.  —  Niagara  group;  Racine,  Wise,  and  Chicago,  Ills. 

Ilciiidrks. — The  basal  concavity  in  the  casts  is  deeper  than  it  appears 
in  the  gutta  percha  impressions,  and  there  are  shallow  grooves  passing  out 
from  it  in  a  radial  direction,  which  are  not  seen  upon  the  impressions,  and 
give  to  the  cavity  in  that  state  of  preservation  a  decidedly  pentapctalous 
aspect.  In  specimens  in  which  the  plates  are  but  partly  dissolved,  the  sur- 
faces generally  show  concentrating  lines  around  the  margins  of  the  plates, 
which  probably  represent  mere  lines  of  growth. 

EuoalyptOCrinUS   VentriCOSUS  W.  and  Sr.  (nov.  spec). 
Plate  LXXXIII.  FhjH.  11  and  12. 

Syn.  EHcalyptocriHHt  cahtiu,  RoEMEn,  1800  (not  Hall  131.3) ;  Silur.  Fauiui  West.  Tcim  , 
p.  48,  Phte  4,  Figs.  3  a-e. 

A  small  species,  in  its  general  form  subovato,  slightly  depressed  at  the 
poles,  its  greatest  width  a  little  above  the  arm  l)ases.  Dorsal  cup  low 
saucer-shaped,  the  sides  evenly  rounded,  its  height  less  than  half  the  length 
of  the  arm  compartments ;  the  plates  flat  or  nearly  so,  marked  in  well  pre- 
served specimens  by  irregidar,  delicate  linos  running  to  the  sides,  but  not 
communicating  with  those  of  adjacent  plates. 

Basal  concavity  narrow  and  very  deep,  obscurely  pentangular  at  the 


■' 


842 


TIIK  CULNOIDKA  CAMKUATA  OF  NORTH  AMERICA. 


outer  margin;  the  basals  very  Rmnll,  occiipyinj.f  only  the  bottom  part. 
Kadials  vury  long,  only  half  their  length  exposed  to  view;  tlje  attenuate 
longer  half  incurving  and  forming  the  sides  of  the  concavity ;  the  exposed 
part  wider  than  high.  Fir.-<t  costals  quadrangular,  their  width  once  and  a 
half  their  length;  the  second  a  little  larger  and  hexangular,  their  upper 
angle  broadly  truncated  by  the  interdistichals.  Distichals  nearly  of  equal 
size,  and  almost  as  large  as  the  axillary  costal;  the  upper  angle  of  the 
second  so  extremely  obtuse  as  to  almost  forni  a  straight  line ;  the  fixed 
])almars  moderately  large  and  (juadrangular.  First  interbrachial  large, 
geneially  as  wide  as  long ;  the  upper  part  broadly  truncated  by  the  two 
plates  of  the  upper  row,  which  together  are  as  large  as  the  first,  and  rise  to 
the  second  arm  plate.  Interdistichal  rather  narrow  and  long.  Partition 
walls  narrow,  not  more  than  half  the  width  of  the  arms,  except  their  upper 
ends  which  widen  conspicuously  toward  the  sunnnit.  Summit  .'(omewhat 
flattened  ;  the  central  space  closed  by  a  short  pyramid  of  small  plates.  The 
arms  rounded  on  the  back,  projecting  slightly  over  the  sides  of  the  parti- 
tions ;  the  three  proximal  plates  single,  and  higher  than  the  succeeding  ones 
which  deeply  interlock. 

Horizon  and  hicuVdy.  —  Niagara  group  ;  Decatur  and  Wayne  Cos.,Teini. 

Ti/pcs  in  the  Museum  of  Comparative  Zoology,  and  in  the  collection  of 
Waehsmuth  and  Springer. 

litindrlin.  —  This  species  differs  from  E.  udatus,  to  which  Roomer 
referred  it  provisionally,  by  the  much  more  depressed  form  of  the  dorsal 
cup,  the  proportionally  greater  length  of  the  arms,  the  form  and  size  of  the 
various  plates,  and  the  mode  of  ornamentation. 

Euoalyptoorinus  orassus  Hall. 
Plate  LXXXI.  Figs.  1,  3,  3,  4,  6,  6,  U,  15. 

1803.     lI.M.i.;  Triiiis.  Albany  lust.,  Vol.  IV.,  p.  107;   also  20lli  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  p.  U\ 
I'lalo  II,  Fiirs.  2,  »  (secniid  cd.,  p.   30.5);  also,  2Slb  Hep.  (second  ed.),   p.  IH,  I'lato  17, 
Figs  1-11,  Plate  18,  Figs.  1-0,  and  Plate  19,  Figs.  2-.5. 
IS'.i.     C)  II.II.L  and  WiiiTFiEi.i);  fi.'ol.  Siirv.  Ohio,  Pabvont.,  Viil.  IT.,  p.  120,  Plate  0,  Fiir.  11. 
ISSl.     Coi.lkt;  lltb  Ann.  Hep.  of  Gool.  and  Xat.  Hist,  of  Indiana,  p.  272,  Plate  17,  Figs.  1-11,  Plato 
IS,  Figs.  1-9,  and  Plate  19,  Figs.  2-5. 
Syii  Fn'itliiptocnnm  roiislriclu',  II.m.l;  ibid.,  p.  273,  Plate  15,  Fi,g.  1. 
Svii.  Eueali/ptocriiiiu  chieagoemis,  WiNcil.  and  Marcy  ;  1805,  Mem.  Boston  Soo.  Nat.  Hist.,  p.  90. 

A  large  species ;  the  crown  sometimes  reaching  a  length  of  10  cm.  by 
6  cm.  in  width ;  its  length,  as  a  rule,  twice  the  width ;  the  length  of  the 


CALYFl'OCKINID.E. 


343 


dorsal  cup  to  the  top  of  the  interbrachiiils  and  iiitoidistichals  ahiiost  ccjual 
to  tlie  liuiglit  of  tlie  compiirtments  for  tlio  reception  of  the  arms.  Dorsal 
cup  subturbinate,  inassivo,  broadly  truncate  at  tlic  lower  end,  and  the 
bottom  part  deeply  excavated,  the  sides  straijjiit  or  a  little  concave ; 
surface  of  the  plates  Hat  and  without  ornamentation ;  the  suture  lines 
obscure. 

Basals  small,  at  the  bottom  of  a  deep,  funnel-shaped  concavity,  and 
forming  with  the  inflected  lower  part  of  the  radials,  at  the  inner  floor, 
a  rather  large  cone  with  a  pentapetalous  axial  canal  of  moderate  siy.e. 
Radials  very  large,  much  longer  than  wide,  forming  a  broad,  slightly 
spreading  cup,  which  extends  out  laterally  far  beyond  the  sides  of  the 
column.  First  costals  quadrangular;  their  length  and  breadth  (([iial;  the 
greatest  width  at  the  base  ;  the  lower  and  lateral  faces  convex.  Second 
costals  .smaller  than  the  first,  generally  pentangular,  occasionally  the  upper 
angle  slightly  truncated  by  the  interdistichal.  First  distichals  almost  as 
largo  as  the  axillary  costals;  the  second  but  one  third  the  size  of  the  first. 
First  palmara  very  short  and  trigonal.  First  interbrachial  almost  as  large 
as  tiie  radials;  length  to  width  as  ;")  to  3;  its  greatest  width  at  the  inter- 
costal suture  line,  whence  it  rapidly  tapers  to  both  ends;  all  sides  concave. 
The  two  plates  of  the  second  row  either  separated  from  the  first,  or  lightly 
touching  its  npper  angle,  and  both  together  .about  two  thirds  the  size  of  the 
first;  they  rise  above  the  arm  bases  in  form  of  n  square  projection.  The 
interdistichal  is  of  a  similar  form  as  the  two  npper  interbrachials,  but  one  third 
smaller.  Ventral  disk,  deprived  of  its  appendages,  pyraniidid,  the  neck-like 
upper  part  proportionally  long,  widening  at  the  top,  the  compartments  .sur- 
rounding it  deep.  These  are  constructed  of  the  keel-like  partitions  ascend- 
ing  from  the  back  of  the  plates  of  the  first  row,  and  the  wing-like  extensions 
of  the  upper  row,  which  meet  each  other  at  the  middle  of  the  third  row, 
resting  with  their  inner  edges  against  the  protruding  surfixces  of  the  plates 
constituting  the  second  and  third  rows.  The  form  of  the  plates  of  the  first 
ring,  as  viewed  from  the  inner  cavity,  is  similar  to  that  of  the  first  inter- 
brachials; they  are  as  large,  and  also  attenuate  at  l)oth  ends.  Tiie  plates 
of  the  second  ring,  which  are  quite  mas.sive  and  elongate,  form  a  leversed 
funnel  with  its  long  tube  pointing  upwards;  those  of  the  third  ring  are 
short  and  narrow,  and  those  of  the  fourth  rather  long  and  wider  aliove  than 
below.  The  canal  within  the  neck  widens  toward  the  extremity,  and  the 
top  is  closed  by  a  short  pyramid  of  small,  irregular  pieces  snrrounding  the 


844 


THE  CKINOIDKA  CAMKIUTA  OF   NORTH  AMKRICA. 


) 


I 


iiiiiiH,  whifli  is  gonenilly  closed  in  the  Mpeciiiiens.  The  edges  of  tlie  partition 
\vall.i  taper  coiLsiderubly  upward,  being  quite  thin  above,  rather  tliick  below. 
Arms  llattened  at  the  back,  stout,  a  little  tapering  at  the  upper  end.  They 
are  conipo.sed  of  extremely  short,  tranverso  pieces,  which  very  wlightly 
interlock ;  the  four  proximal  joints  wingle  and  resting  between  the  protrud- 
ing upper  parts  of  the  intcrbrachials  and  interdistichals.  In  very  nuiture 
specimens,  in  which  tlie.se  projections  are  comparatively  longer,  tiiey  some- 
times enclose  5  to  G  joints.  Column  tapering  downward,  the  joints  much 
the  longest  at  the  upper  end ;  the  nodal  joints  long,  and  wider  than  the 
intervening  younger  ones,  their  outer  margins  slightly  convex;  the  joints 
near  the  root  very  short  and  of  uniform  size.  The  root  is  composed  of  hun- 
dreds of  small  branchlets,  most  of  which  arc  run  out  horizontally. 

IIui'!.""n  dial  Localit//.  —  Niagara  group;  Waldron  and  llartsville,  Ind., 
Green  Co.,  0.,  and  Chicago,  Ills. 

Tijpes  in  the  American  Museum  of  Natural  History  at  New  York. 

RviiKirlcii.  —  This  .species  is  extremely  variable  in  form  and  proportions, 
but,  as  iv  rule,  the  cup  in  the  older  specimens  is  more  elongate,  and  not 
unfrequently  constricted  near  the  middle,  thereby  producing  a  sliglit  con- 
cavity at  the  sides.  The  ba.se  in  .some  specimens  is  so  broad  as  to  give  to 
the  cup  a  subcylindrical  outline.  In  all  specimens,  however,  the  base  extends 
far  out  beyond  the  sides  of  the  stem,  and  this,  together  with  the  unusual 
length  of  the  first  costals,  and  the  extreme  .  hortness  of  the  arm  joints, 
distinguishes  it  readily  from  all  other  American  species  of  this  genus. 

Euoalyptocrinus  ovalis  (Troost)  Hall. 
Plate  LXXXII.  Fitjs.  1,  2,  3,  4,  S,  6. 

1819.     EueulyploeriiiHs  ovii/ia  —  Troost;  Ciitalogue  of  Criiioidca. 

1874.     Euc(i///ji/oi-riiitt.t  oi;i/ii.i  (in  error  lor  E.  ovn/ix)  —  IIai.i.;  first  rdil.  28tli  Hep.  N.  Y.  State  Miis.  Nnt. 

Hist.,  I'liitc  17,  I'igs.  12  ami  13  (the  error  rectificil  in  the  secoud  edit,  of  tlio  same  report  in  the 

exphinnlii)ii  of  the  plates). 
1S83.     Eiii-ii/yjifmriiiiis  uvii/ia  —  W.  and  Sp. ;  Rcvibion  PaliEocr.,  Part  ITT.,  p.  134. 

A  small  species.  General  form  ovoid,  curving  regularly  from  base  to 
summit.  Height  to  width  as  four  to  three  in  mature  specimens,  and  six  to 
five  in  very  small  ones.  Greatest  width  a  little  above  the  top  of  the  dorsal 
cup.  Height  of  the  cup,  compared  with  the  height  of  the  partition  walls,  as 
two  to  three.  Surface  of  plates  smooth  and  without  ornamentation ;  the 
suture  lines  indistinct. 


1 

• 

CALYPTOCllIMD.E. 


846 


Bftsal  concavity  a  little  wiilcr  tlinn  the  column,  and  rather  deep,  the  bns<al 
plates  occupying  almost  its  whole  width.  Ikdials  curving  abruptly  inward 
nt  the  lower  end,  forming  n  sharp  edge  at  the  bottom  of  the  dorsal  cup ;  the 
exposed  npper  part  wider  than  long,  and  nearly  as  large  as  both  costals  to- 
gether. First  costals  once  and  a  half  as  wide  as  long  ;  the  second  a  little 
wider  and  pentangular.  First  disticlmls  almost  as  large  as  the  costals,  the 
second  one  third  smaller,  and  the  arm-bearing  palmars  about  linlf  the  size  of 
the  second  distichals  and  pentangular.  First  intorbrnchial  large,  subcirculnr 
in  outline  though  actually  decagonal ;  it  meets  the  two  succeeding  plates, 
which  are  as  long  as  the  first,  and  near  the  lower  end  almost  as  wide ;  the 
upper  parts  tapering  rapidly  to  a  rather  sharp  point,  which  rises  to  the  height 
of  the  fourth  arm  pieces.  Interdist'chal  narrower  and  shorter  than  the  two 
upper  interbracliials  ;  the  lower  end  angular  and  barely  touching  the  upper 
angle  of  the  adjoining  costal ;  the  projecting  upper  end  narrow  and  truncate. 
Compartments  for  the  reception  of  the  arms  deep ;  the  partition  walls  thin 
throughout,  their  width  at  the  lower  end  half  that  of  the  arms,  the  outer  faces 
flat.  The  summit  closed  by  a  small  rosette  of  about  eight  pieces  without 
additional  plates.  Arms  very  gradually  tapering,  the  outer  face  slightly 
convex  ;  they  are  composed  of  moderately  short  pieces,  which  interlock 
from  the  fourth  plate.  With  the  exception  of  the  partitions  nothing  is 
known  of  the  construction  of  the  disk.  Column  round,  the  no'lal  joints 
high  and  cylindrical,  the  younger  joints  a  little  narrower;  axial  canal 
pentalobate. 

Horizon  and  Localiti/.  —  Niagara  group  ;  Waldron  and  Ilartsville,  Ind. 

Ti/pcs  in  the  American  Museum  of  Natural  History  at  New  York. 

lictnarks.  —  This  species  has  such  close  affinities  with  .E".  c>t<.s'.s!<s  that  it 
might  be  taken  for  its  younger  stage ;  but  on  close  inspection  it  will  be  ob- 
served that  the  specimens  have  all  the  characteristics  of  an  adult  form.  The 
arms  not  only  are  biserial,  but  their  plates  are  almost  transversely  arranged. 
Moreover,  the  arms  are  placed  deeply  in  between  the  projecting  upper  ends 
of  the  interbracliials  and  interdistichals  ;  only  in  young  specimens  the  tips 
are  almost  on  a  level  with  the  distal  faces  of  the  arm-bearing  palmars.  It 
differs  from  E.  crassus  in  its  much  smaller  size,  being  only  from  12  to  22 
mm.  in  length  by  from  10  to  15  mm.  in  width,  in  the  more  evenly  ovate 
form  of  the  crown,  in  not  being  truncated  at  the  lower  end,  and  in  having 
much  shorter  cost'',ls,  and  proportionally  larger  and  pentangular  arm-bearing 
palmars. 


'■\3ir»*r 


840 


rilK  CKINOIDEA   CAMKHATA  OF  NOHTII   AMKUICA. 


if 


EuoaljrptoorinuB  inoonspeotus  RiNduenEKo. 
J'/iitc  LXXXIIL  Fi.js.  1  and  J. 

ISSt.    lliNQLEiiKiui ;   I'rocml.  Aeiul.  Niit.  Sci.  I'liiU.,  p.  MS,  I'lutc  3,  Fig.  5. 

Of  ratlior  largo  size.  Dorsal  cup  deep,  occupying  almost  one  half  of  the 
length  of  tiio  crown  ;  semi-ovoid,  the  sides  decidedly  convex,  rising  gradu- 
ally to  the  middle  of  the  second  costals,  thonco  almost  vertically  to  the  top, 
so  that  the  plates  at  the  upper  end  are  parallel  to  those  of  the  o])posito  side. 
Plates  flat — the  general  curvature  excepted  —  and  without  ornamentation 
or  other  markings,*  the  suture  lines  indistinct. 

Basal  concavity  narrow  and  fdled  completely  by  the  upper  part  of  the 
column.  Radials  about  as  long  as  their  width  near  the  top,  rapidly  tapering 
downward,  the  extreme  lower  end  gently  curving  inward  and  taking  part  in 
the  columnar  concavity;  the  sloping  upper  faces  very  short.  First  costala 
as  wide  as  long,  a  little  narrower  at  the  upper  end,  the  sides  slightly  convex. 
Second  costals  as  long  as  the  fust,  widest  at  two  thirds  their  height,  some- 
times the  upper  angle  slightly  touched  by  the  interdistichals.  First  distichals 
a  tliird  smaller  than  the  upper  costal,  the  second  very  small,  and  the  .suc- 
ceeding palmars  still  smaller  and  irregularly  pentangular.  First  interbrachial 
extremely  large,  decagonal,  about  a  third  longer  than  wide,  attenuate  at 
both  ends ;  the  two  of  the  second  row  shorter,  and  together  narrower  than 
the  first,  their  upper  and  lower  ends  forming  re-entering  angles.  The 
interdistichal  approaching  the  two  upper  interbrachials  in  form,  but  con- 
siderably smaller;  its  upper  end  squarely  truncated,  and  rising  to  the  third 
arm  plate.  Partition  walls  narrower  than  the  arms,  and  of  uniform  width 
throughout ;  their  outer  edf.fos  flat  at  the  proximal,  and  convex  at  the  distal 
enil.  Arms  gradually  tapering,  rounded  exteriorly ;  the  three  lower  joints 
single,  and  a  little  longer  than  the  upper,  which  arc  extremely  short.  Struc- 
ture of  disk  and  summit  unknown. 

Horizon  and  Locidifi/.  —  In  the  white  limestone  at  the  upper  part  of  the 
Niagara  group  ;  Rochester,  N.  Y. 

Jicmarh.  —  Nearest  to  /:,'.  cntxi^uft,  but  the  sides  of  the  dorsal  cup  dis- 
tinctly rounded,  the  base  not  truncated,  and  the  ba.sal  concavity  very  much 
smaller. 

•  HinpfiirbprR  drspribnl  the  siirfiire  ns  "  firirly  riignsp ;  rugir  giviiij^  evidence  of  irrrguliir  radintioiis 
from  llir  lar^'or  |il,ili's."  \Vi!  jiiivi'  raicrutly  cMiiiiiiMMl  his  lyiic,  but  cannot  discover  nny  onmniciitution ;  tlio 
rouglnipss  upon  the  surface  is  evidently  caused  by  weathering. 


II 


CALYinOCHINID.K. 


347 


EuoalyptoorlnuB  Lindahll  W.  &  Sp.  (nov,  npoc.) 
Plate  LXXXII.  Fifj.  9. 

18M.     Amoricnn  Gcnliijfist,  VdI.  \.  (Sriilcjiliri),  [i.  l.H). 

Sjii.  Eiiiuili/iiliK'i-iimi  ll'ur/inii  S.  A.  Mmi.kiii   1S91,  Gcol.  Hip.  Ill,,  null,  3,  p.  fiS,  I'lali'  t,  Fijj-  i. 

Above  inediiuii  wizo.  Most  roiniukiiblo  for  its  heavy,  roumlod  aims,  which 
to  their  full  Icnjjth  are  oleviiteil  proiiiinentiy  iiliove  the  outer  fiiceH  of  the 
partitioii  walls,  so  that  the  liitter  form  the  bottom  of  a  deep  groove.  Doiwil 
cup  seiiii-globoso,  its  lower  concavity  not  larger  than  the  width  of  the  stem, 
and  enclosing  only  the  ba.sal.s,  which  are  hidden  from  view  by  a  narrow, 
round  stem.  IMutes  not  distinctly  orimmented,  merely  showing  u  roughened 
surface.     Suture  lines  slightly  grooved. 

Riidiiils  rather  large,  as  long  as  wide,  rapidly  .sloping  to  the  lower  end  ; 
their  lateral  faces  three  times  ns  long  ns  the  slanting  \ipper  ones ;  tin- 
superior  face  concave.  First  costals  quadrangular,  smaller  than  the  rndi- 
als,  a  little  wider  than  long.  Second  costals  hexangular,  wider  and  longer 
than  the  first;  their  .sloping  upper  faces  longer  than  any  of  the  otht-rs ;  the 
npper  angle  slightly  truncated  by  the  interdistichal.  First  distichals  smaller 
than  the  axillary  costals,  the  .second  less  than  half  the  size  of  the  fir.>t,  nnd 
subquadrangulir.  Palmars  three  in  the  calyx,  l  ransver.sely  arranged,  rounded 
on  the  back.  First  interbrachial  ten-sided,  os  large  as  the  radials.  longer 
than  wide,  widest  at  the  middle  ;  the  two  of  the  second  row  nearly  three 
times  as  long  as  wide,  rising  to  the  height  of  the  third  palmars.  The  inter- 
distichal a  little  .shorter  and  narrower  than  the  two  upper  interbrachials  com- 
bined. The  walls  forming  the  compartments  taper  gradually  to  near  the 
upper  end,  then  widening  rapidly,  and  curving  abruptly  inward  so  as  to  form 
a  Hat  surface  at  the  summit  on  a  level  with  the  tips  of  the  arms.  Arms 
rather  short,  very  heavy,  almost  cylindrical.  They  rise  above  the  sides  of 
the  partitions  much  more  conspicuously  than  is  known  to  be  the  case  in 
any  other  species,  their  tips  being  lifted  out  from  between  them  almost 
completely. 

Horizon  and  Loralitij.  —  Niognra  group ;  Wayne  Co.,  Tenn. 

Ti/pp  in  the  Illinois  State  collection. 

The  species  is  named  in  honor  of  Dr.  Josua  Lindahl,  the  eminent  Zoolo- 
gist and  Director  of  the  State  Museum  at  Springfield. 


IB 


TT^sm 


^xapwtir. 


1 


<> 


348 


TIIK  CHINOIDKA  CAMEKATA  OF   NOUTII   AMKRICA. 


Eucalyptooiinui  magnus  Woktiikv. 

I'tutf  l.XXX/l.  Fl;/x.  7,  S. 

1S7S.    Woutiikn  1  ami.  Hip.  Illiii<ii>,  Vnl.  VI  ,  p.  sol,  Pluls  ij,  Fig.  3. 
iHiiJ.     \V.  iimlM-.  ;    Ui'tiMcm  I'lilivocr  ,  Purl  III.,  |>.  l:i:i. 

«vii.  Kiii'iilitiilm-fiiiHii  (iiiibi/i  S.  A.  ^liLLku  i   Ailv.  Hlit'cli  17tli  Itrp,  Gcul,  Surv.  Miuourii  p.  30, 
I'lulr  7,  FiK".  5,  0, 

A  liirgo  M|iet'ic'.>(.  Doisiil  cup  doprtwetl  tiirbiiiiUt',  liui^lit  ninl  wiiltli  uliont 
lis  Mcvi'ii  to  ton  ;  tlie  lowor  end  obtiLsoly  coiiiciil,  riipiilly  Hpiemliiij,'  IVom  tlio 
top  of  till'  iiuliiils  to  tlio  top  of  llio  lii'Mt  iliwlicliiilM,  tlu'ii  abniptl_y  tiirniiij( 
iipwurili  until  nt  thu  uppc>r  end  tliu  HiduH  iiru  piirullul  witli  tlio.xc  of  tlic  oppo- 
Hito  side.  Tlio  upper  interbnicliiiilH  Hoinewliut  dupreHst-d,  ho  as  to  give  to  llio 
cup,  a.i  Hoen  from  above,  an  olwcuruly  peutalobato  outline.  I'liile.s  alinowt 
Hat ;  tbu  Hurfiu'o  sinootii  or  finely  granulow  ;  Huture  lines  wli^litly  j,'i'ooved. 

Itasal  concavity  niurow,  completely  filled  by  tbu  column.  Kadial.s,  an 
exposed  to  view,  wider  tluin  long,  rapidly  wjireading  upward,  tbeir  upper 
fiices  twice  as  wide  as  the  lower.  Firnt  costaln  Homewbat  Huudler  and  (|uad- 
rangular;  tbe  sides  sliglitly  convex.  Second  costals  beptangular,  wider  and 
Idiijjer  tbiin  tbe  first ;  tbe  sloping  upper  faces  convex  and  unusually  sleep  ; 
tbe  upper  angle  broadly  truncated  by  tbe  interdisticbal.  First  dislicbnls  as 
large  as  tbu  axillary  costal  ;  tbe  Mccond  less  tlian  lialf  tbe  si/u  of  tbe  fir.st; 
tbu  arm-bearing  palmars  trigonal  and  cjuitu  small.  First  interbracbials  tbo 
largest  plates  of  tbe  cup;  decagonal,  but  sub-rbomboidal  in  outline;  tbe  sides 
more  or  less  concave.  Tbu  two  plates  of  tbe  second  row  togetber  wider  tbiin 
tbe  first,  witb  re-entering  angles  at  tbe  upper  and  lower  ends.  Interdis- 
ticbiils  large,  elongate,  rising  to  tbe  bcigbt  of  tbe  fiftb  arm  plate,  tbe  sidea 
fiicing  tbe  costals  concave,  tbe  upper  and  lower  faces  broadly  truncated.  Of 
tbe  arms  only  a  few  of  tbe  lower  plates  were  preserved,  wbich  are  extremely 
sbort.  Tbe  partition  walls  are  broken  away  in  tbe  specimens,  but  were,  to 
judge  from  tbe  places  for  tbeir  attacbment,  imusuolly  beavy. 

Horizon  and  Localih/.  —  Niagara  group;  Wbitu's  creek,  near  Nasbvillu, 
Tenn.,  and  Decatur  and  Wayne  Cos.,  Tenn. 

T^pe  in  tbe  collection  of  Prof.  S.  S.  Gorby. 

lieniarks.  —  Tbis  si)ecies  is  most  remarkable  for  its  large  size,  and  is 
readily  distinguisbcd  from  all  otber  known  spucies  by  its  peculiar  form. 


'f/ 


C'Ar.YPTOCRINID^Ii:. 


840 


< 


EuoalyptOTinui  deproiaus  ^^  A.  Mh.i.kk. 

riuu  Lxxxiii.  Fiijs.  .J,  4„,  4b. 

wo     8.  A.  Mii.i.iiii  Jiiiim.  Ciiiciii.  Hiip.  Nut.  Ilinl.,  Vol.  III.,  p.  fM,  I'liili  7,  V\\(i.  I,  In,  i. 
my    \f.  ami  Hr.i  lluvitiuii  ruliiiicr.,  i'art  III.,  |i.  l»a. 

Of  inodunito  hIzc.  Crown  Hiihc^liiuliiial,  twico  iih  liigli  m  \\'u\o,  a  littlo 
tnporing  to  the  iippor  ciid,  iliMtiiictly  tliitteiiLMl  mid  concnvo  at  tlio  puloH, 
Dui'Miil  cup  alnic-^t  twice  as  wide  uh  high,  the  upper  p'irt  of  the  rudials  and 
thu  cxircino  ciid.s  of  tho  lirst  inloihrachials  roriniiig  the  tniiicatcd  liottoin, 
the  iippct  part  of  the  hitter  and  the  fir^t  costal^  gently  curving  npwurd,  the 
plates  ahove  parallel  to  thoHe  of  the  opposite  Hide.  Plateii  a  little  convex, 
their  Hiirfnce  ap[)areiitly  riigo.se.  Lower  concavity  deeply  and  hroadly  fnn- 
nel-shaped,  the  hasal-s  constituting  hut  little  more  than  the  bottom  part. 

Kadials  slightly  longer  than  wide;  their  upper  half  more  or  le.xs  ho;i- 
zontal  in  position,  and  not  visible  from  a  side  view  ;  thu  luv.er  half  lorming 
the  slanting  sides  of  the  concavity;  their  sloping  upper  faces  rather  long. 
First  cottals  twice  as  wide  ns  long,  a  little  .shorter  than  the  second  at  the 
median  line;  the  u|)pcr  end  of  the  latter  hlightly  truncated  by  the  inter- 
distichal.  First  distichals  about  a  third  snudler  than  the  upper  costals  ;  tho 
second  half  the  size  of  the  Hrst,  their  upper  angles  (juite  obtu.se;  the  first 
palmars  very  small  and  peiitiingular.  First  interl)rachial  subrotundate,  as 
long  as  wide,  those  of  the  second  row  m  long,  but  together  narrower  than 
the  fust,  their  upper  ends  rising  to  the  base  of  the  second  arm  |)lates.  'i'ho 
interdistichal  ha.s  almost  the  form  of  the  two  upper  intcrbrachial.s,  but  is 
somewhat  smaller.  Partition  walls  nearly  twice  as  long  as  the  dor.sal  cup, 
moderately  thin,  the  outer  edges  rounded  to  near  the  top,  then  slightly  widen- 
ing and  curving  abruptly  inward  and  somewhat  downward,  so  as  to  form  a 
shallow  depression  around  the  summit.  Their  upper  ends  enclose  five  rather 
largo  plates  with  a  pentangular  open  space,  the  overlying  plates  being  not 
preserved  in  the  specimen.  The  height  of  the  calyx,  as  ob.served  in  the  casts, 
is  about  equal  to  the  greatest  width  acro.ss  the  fir.st  distichals,  and  that  of 
the  dorsal  cup  ecpial  to  that  of  the  tegmen  but  narrower;  the  tubular  pro- 
longation above  almost  as  long  as  the  rest  of  the  calyx,  nidening  at  both 
ends.  Of  the  arms  only  the  proximal  plates  are  preserved,  which  are  com. 
paratively  long. 

Horizon  and  Locality.  —  Niagara  group;  Cicero  and  Bridgeport,  near 
Chicago,  Ills. 


-fsm 


■'ssm-mm^ 


350 


THE  CKINOIDKA  CAMERATA  OF  NORTH   AMERICA. 


^ 


f 
III      ^|i 


T//pes  in  the  collection  of  \V.  C.  Egnn,  Esq.,  of  Chicngo. 

Ilanurks.  —  Tiiis  Hpceies  diflcrs  from  nil  preceding  ones  in  the  depressed 
form  of  the  dorsal  cup,  the  width  and  depth  of  the  hasiil  concavity,  and  the 
po.-iition  of  the  radials  which  are  almost  at  right  angles  to  the  plates  of  the 
np;  or  end.  It  was  originally  described  from  natural  casts,  but  Mr.  Egan 
has  dnco  obtained  from  the  same  locality  a  specimen  with  the  plates  intact, 
from  which  our  description  is  made. 

Duitbtfal  species  described  from  natural  casta,* 

EuoalyptOOrinUS    Sple^didUS  (Troost)  Ham.  ami  AVuitfikld. 

1818.     Troost  ;  List  Criii.  Tciiii.,  Proceed.  Aiiicr.  Assoc.  Adv.  Sci.,  p.  60  (willioiit  desciiplion). 
1873.     Hall  and  Wuitfikld  ;  Geul.  Surv,  of  Ohio,  I'lda-out.,  Vol.  II.,  p.  XL'S,  Plate  0,  Fig.  12. 

Closely  allied  to  the  preceding  s[)ecies,  and  perhaps  identical  with  it. 
As  in  that  species,  the  general  form  is  subcylindrical,  linttened  at  both  ends, 
the  arms  are  twice  as  long  as  the  dorsal  cup,  and  the  radials  are  not  seen  in 
a  side  view,^or  only  their  extreme  ujjper  ends;  the  disk,  however,  to  judge 
from  the  cast,  is  proportionally  sliorter,  and  the  first  costals  are  higher.  The 
basal  concavity  cannot  be  seen  in  the  specimen,  but  must  have  included  the 
preater  part,  if  not  the  whole,  of  the  radials.  First  castals  quadrangular, 
nearly  as  long  as  wide ;  the  apex  of  the  second  slightly  truncated  by  the 
interdistichai ;  the  distichals  considertbly  smaller  than  tiie  costals  ;  the  first 
interbrachiiil  large,  a  little  longer  than  wide  The  proportions  of  the  other 
plates  indeterminable.  Disk  hemispherical,  the  tubular  canal  in  the  cast  as 
long  as  the  rest  of  the  calyx,  and  funnel-shaped  at  the  upper  end. 

Horizon  awl  LocnHtij.  —  Niagirra  group  ;  Springfield,  0. 

Tifpe  in  the  collection  of  Professor  Orton. 

Euoalyptoorinus   rotundus  s.  A.  :MiLi.En. 

18S2.     S.  A.  MiLLKii ;  Jourii.  Ciiiciii.  Soc.  Nat.  lli-t.,  Vol.  V.,  p.  82,  Plate  3,  Figs.  4  and  4  n,  /;,  c 

Of  small  size.  Crown  globose.  The  inner  cavity  of  the  calyx,  as  seen 
in  the  cast,  much  wider  than  high,  the  canal  within  the  neck  wide  and  of 
nearly  uniform  width.  Dorsal  ciip  low-saucer  shaped ;  the  basal  concavity 
small,  and  apparently  filled  completely  by  the  upper  joints  of  the  column. 
Radials  wider  than  long,  the  upper  face  concave.     First  costals  twice  as  wide 

*  We  arc  willinn  to  admit  that  most  of  these  forms  differ  s|icci(leally  from  one  another,  l)ut  we  arc 
unable  to  see  liow  the  casts  can  hi'  satisfactorily  compared  with  species  described  from  the  test,  especially  in 
a  genns  like  Eiiail^vplorrimis  in  which  the  dilTerentiations  arc  but  very  slight. 


CALYPTOCRINID^E. 


351 


ns  long.  Second  costals  about  the  size  of  ,iie  first,  a  little  higher  at  the 
median  line,  their  upper  end  slightly  truncated  by  the  interdistichal.  First 
distichals  almost  as  large  as  the  costals.  The  form  of  the  other  plates 
indeterminable. 

Horizon  and  Lomlihj.  —  Niagara  group ;  near  Chicago,  Ills. 

'rijpes  in  tiie  collection  of  W.  C.  lOgan,  Esq.,  oi"  Chicago. 

lianarJcs.  —  Thi.s  may  be  a  small  specimen  of  E.  Elrodi,  with  which  it 
agrees  in  the  general  form,  and  in  the  proportionate  size  of  the  plates. 


Euoalyptoorinus  turbinatus  s.  A.  Milleb. 
Plate  LXXXIL,  FUj.  13. 

18S2.     S.  A.  M11.1.EH  ;  Joum.  Ciiicin.  Soc.  Kiit.  Hist.,  Vol.  V.,  p.  S2,  Plato  3,  Figs.  5  ami  5  a. 

A  rather  large  .species.  In  the  cast,  the  calyx  is  nearly  as  high  as  wide, 
the  dorsal  cup  obconical,  slightly  constricted  above  the  radials,  the  extreme 
upper  end  abruptly  curving  upwards ;  the  suture  lines  are  defined  by  angu- 
larities, and  the  inner  spaces  of  the  plates  are  slightly  concave.  Tlie  disk 
appears  depressed  hemispherical,  with  ten  well-marked  longitudinal  ridges 
representing  the  ambulacral  grooves. 

Bisal  concavity  moderately  deep  and  obscurely  pentangular.  Eadials. 
as  exposed  in  a  side  view,  comparatively  snuill,  wider  than  long.  First 
costali  quadrangular,  m-arly  as  long  as  wide.  Second  costals  pentangular, 
a  little  larger  than  the  first,  the  sloping  upper  sides  steep,  the  upper  angle 
truncrted  by  the  interdistichal.  First  distichals  as  large  as  the  second 
costal ;  the  second  much  smaller  ;  the  palmars  minute.  First  inteibrachial 
a  tliinl  longer  than  wide,  barely  touching  the  radials.  The  two  plates  above 
forming  a  rhomb  with  tlie  two  acute  angles  truncated.  Interdistichal  com- 
paratively short.  Length  of  the  partition  walls,  and  the  neck-like  prolonga- 
tion of  the  calyx  not  known. 

Iluraon  and  Locidil;/.  —  Same  as  last. 

l)jl>e  in  tiie  collection  of  Mr.  W.  C.  Egan. 

livmarhs.  —  This  is  probably  a  good  species.  Fragmentary  .«!pccimens 
with  the  plates  intact,  apparentl}'^  representing  this  form,  occur  in  the 
Niagi.ni  group  of  Decatur  Co.,  Tenn.  The  basal  concavity  is  narrow,  and 
the  radials  have  a  truncation  at  the  bottom,  of  which  the  edges  project 
rather  broadly  over  the  sides  of  the  column.  The  truncated  upper  faces 
of  the  ii:terbrachials  and  interdistichals  supporting  the  partition  walls  are 


352 


TIIK  CRIXOIDKA  CAMERATA   OF  NORTH  AMERICA. 


extremely  wide,  the  facets  for  the  reception  of  the  arniH  are  surrounded  by 
a  raised  angular  edge,  and  the  plates  are  covered  with  obscure  radiating 
ridges  or  rows  of  small  tubercles. 

Euoalyptocrinus  Egani  s.  A.  ^riLi.i;n. 

Phtte  LXXXIL  Fiijs.  11  ami  12. 

18S0.     S.  A.  MiLLKii;  .liiurii.  C'iiiciii.  Soc.  Niit.  llisl.,  Vul,  III.,  p,  140,  rinle  4,  Figs.  1  a-c. 

A  very  elongate  species.  Height  and  width  of  calyx  as  8  to  5 ;  height 
of  dorsal  cup,  compared  with  the  length  of  the  arms,  as  2  to  5;  the  length 
of  the  neck-liko  prolongation  to  the  tips  of  the  partitions  as  8  to  9  —  all 
measurements  made  from  the  casts.  Dorsal  cup  a  little  higher  than  wide, 
obconical,  the  bottom  distinctly  truncated  and  not  excavated  in  the  cast, 
the  sides  very  "^lightly  convex  and  projecting  conspicuou.><ly  oA'or  the  sides 
of  the  disk.  Radials  nearly  as  long  as  wide.  The  first  costals  longer  than 
wide,  and  narrower  above  thiin  below ;  the  second  of  the  same  length,  and 
truncated  l)y  the  interdistiehals.  Distichals  a  third  smaller  than  the  costals. 
First  interbrachials  almost  twice  as  long  as  wide,  widest  at  midway.  Form 
of  the  remaining  plates  indeterminable.  Ventral  disk  but  sliglitly  tapering, 
its  upper  margin  curving  abruptly  to  the  liase  of  tlie  neck,  which  expands 
rapidly  upwards.  It  ri.'<es  apparently  far  beyond  the  arms,  and  tapers  in  size 
as  rapidly  as  it  increases  below. 

Horizon  and  Locality.  —  Same  as  last,  and  the  type  specimens  in  the  same 
collection. 

Euoalyptocrinus  probosoidalis  8.  A.  Milleu. 

Plate  LXXXII.  Fly.  U. 

1882.    S.  A.  Miller-,  Journ.  Ciiicin.  Soc.  Xnl.  Hist.,  Vol.  V.,  Tlntr  9,  Fig.  2. 

Closely  allied  to  the  preceding  species,  but  the  calyx,  to  judge  from  the 
cast,  still  more  elongate,  being  to  the  b  .«e  of  the  neck  over  twice  as  long  as 
wide;  the  sides  of  the  dorsal  cup  more  convex;  the  tegmen  higher  propor- 
tionally, less  depressed  at  the  toj),  and  nu)re  evenly  rounded.  The  neck  is 
more  constricted  in  the  middle,  and  more  expanding  at  the  summit,  the  tube 
succeeding  it  thicker  at  the  base,  and  apparently  longer,  reaching  in  the 
type  a  length  of  4.3  mm.  by  12  mm.  in  width  at  the  base,  and  2  nrn.  at  the 
upper  end,  tapering  giadually.  The  plates  of  the  dorsal  cup,  so  far  as 
observed,  are  long,  especially  the  first  interbrachials,  which  are  more  than 


m\ 


II 


CAF-YITOCRINIDTE. 


353 


twice  ns  long  as  wide,  occupying  fully  one  half  the  length  of  the  dorsal  cup. 
The  tube  in  its  free  state  was  covered  by  large  hexagonal  plates,  very 
regularly  arranged. 

Horizon  and  LomJit//.  —  Niagara  group;  Pontiac,  O. 

Remarks.  —  Miller  descril)ed  this  species  from  a  plaster  cast  in  the  pos- 
session of  Mr.  A.  McCord  of  Oxford,  Butler  Co.,  0. 

Euoalyptoorinus  oboonious  Hall. 
Plate  LXXXIIL,  Fly.  13. 

ISfi?.     HALt.;  aoili  Rep.  N.  Y.  StnUi  Miisimm  Nnt.  Hist.,  p.  32.1,  Plate  11,  Tig.  1. 
IS?.).     W.  mid  Sr. ;  llcvlsiuii  rak-oor.,  I'lirt  III.,  p.  Ilia. 

Diflering  from  all  other  American  species  of  this  genus  in  the  arrnnge- 
nieut  of  the  basols,  wliich  form  an  ol)conical  cup  instead  of  being  placed 
within  a  concavity.  Dorsal  cup  very  long,  sometimes  almost  twice  as  high 
as  wide,  sharply  pointed  at  tiie  lower  end.  the  sides  straight  to  near  the  top, 
wliere  they  slightly  contract.  Radials  once  and  a  half  as  long  as  wide,  but 
very  little  tapering,  the  sloping  upper  faces  (|uite  small.  First  costals 
(|uadrangular,  as  long  as  wide,  tlie  upper  face  narrower  than  the  lower;  the 
second  costals  of  almut  the  same  size  as  the  first,  but  pentangular.  Fir.st 
distichals  comparatively  largo,  those  of  the  same  ra}' in  contact  laterally; 
the  second  very  small.  First  interbrachials  nearly  twice  as  long  as  wide, 
widest  at  nii<lway ;  the  two  of  the  second  row  shorter.  IrUerdistichals 
unusually  small,  resting  upon  llie  .-^loijing  upper  faces  of  the  first  distichals. 
All  other  parts  unknown. 

lIurizoH  and  Localilij.  —  Niagara  group  ;  Kacine,  Wise,  and  Chicago,  Ills. 


CALLICRINUS  i.'OimKiNv. 

IS'iU.     D'OuiilONY  (r.////o(Y/«ffs);  rnidmnip,  Vol.  1.,  p.  45. 

1878.     A.N(iKi,ls;   leonngr  Clin.  Slice,  p.  1 1. 

1S;9.     ZiTiKi.;  Ilamll).  il.  I'alrediit.,  Vol.  I.,  p.  378. 

18M.     W.  and  Si'.  ;  Hc\i»ion  I'idirocr.,  rait  III.,  p.  l.l.')  (Proceed.  .\i'ad.  Niil.  Sci.  riiiln.,  p  .IS?). 

1891).     HlxotKiiKlUi ;  .\iiimls  \    Y.  .Vend.  Sci  ,  Veil.  V.,  p.  ;i()2. 

Syn.  Kiiiii-iiitirriiiiln  Hisixom  (mil  .1.  S.  .Miller),  ls.")7.  Lclliiea  Suep.,  p.  8(1. 

Syn.  EH,-iihji,lnrrhiii>  (in  part)  lUl.l.;  X.  Y.  State  Mus.  Xat.  Hist.,  p.  322  (20ili  Hep ). 

In  its  general  a,spect,  in  the  form  of  .he  calyx  and  arrangement  of  the 
plates,  closeh'  resembling  Encnh/ptncrlnus.  The  calyx  also  lias  the  form  of 
a  wine  bottle  with  long  slender  neck,  and  a  deep  concavity  at  the  bottom  ; 
but  the  partition  walls,  instead  of  forming  clewed  compartments  to  the  full 

45 


864 


THK  t'KIXOlDKA   CAMKR.VTA   OF   NOKTII  AMKUICA. 


>J 


■  i , 


Icnyth  of  tlie  nriiis,  rise  only  to  a  certain  liciglit,  and  are  not  closed  from 
above.  The  plates,  as  a  rule,  are  liij,'lily  ornamented,  strongly  nodose,  or 
cxtiiuled  into  long  spines.  The  dor.sal  cup  is  constructed  of  tlie  same  num- 
ber of  plates,  and  arranged  in  exactly  the  same  manner  a.s  in  EHvuhiptovrinm; 
generally,  however,  tlie  basal  concavity  is  wider,  and 
only  partly  filled  by  the  coliunn.  In  the  construction 
of  the  ventral  disk  also,  the  two  genera  have  close 
affinities ;  the  plates  in  both  forms  consist  of  foin* 
rings,  and  in  both  of  them  the  first  ring  is  composed 
of  twenty  plates,  the  second  and  third  of  four  ;  but 
the  fourth  ring  contains  but  four  plates  instead  of  ten. 
and  these  have  no  wing-like  extensions  at  their  outer 
faces ;  the  upper  parts  of  their  arms  are  free,  and  rest 
directly  against  the  walls  of  the  anal  tube.  The  parti- 
tion walls,  of  which  there  are  twenty  in  this  genus, 
are  restricted  to  the  plates  of  the  first  ring,  and  rise 
but  little  above  their  general  height,  never  touching 
the  plates  of  the  second  ring.  Five  of  the  partitions 
are  su|)portc'd  by  the  interbrachials,  five  by  the  inteV- 
distichals;  the  remaining  ten  are  interposed  between 


Fui.  17.  C<iltirrinuf.  Siilo  view 
of  nilyx,  ^liiiwiut;  the  niili- 
nu'iilarv  hiirliliuni.. 


K  ~  railials ;  /  —  conlalx  \  II  = 
(listiclinU;  lAr  -  in(erl»rni>lil- 
tl>i  ill  inliT'livtii'lml*;  irV 
=  intcrriuiidl  )inr(itiiili!t :  /'//* 
—  inliTdimivlKil      iiarliilMiiH; 

!>/'    intirpiiiniar  i.ariiii..iii.;    tlic  tcH  otlicTs,  and  Tcst  upon  tlic  cdgcs  of  two  palmars. 

/  =  llit'  llrsi  or  IipwiT  rinir  of      riii  i    *x  ^'i'  c  i    i  •         im  i 

,,i«t,.,  i„  ,1,..  ..KM. .on,,    ll'es'e  latter  partitions  are  formed  by  wmg-like  exten- 

poH.Ml  of  IcH  larifc  ami  len 
piniill  sutitri^iinnl  |iii'ce!«;  2  ~ 
tlie  |ilul4'H  itf  the  i*eci)ii<l  rhi^, 
.1  =  thone  of  the  third  ritif;, 
^  —  the  platen  of  the  fourth 
ring. 


sions  from  the  ten  .smaller  plates  of  the  first  ring; 
they  rise  to  the  .same  height  as  the  others,  and  separate 
the  two  arms  which  in  Kiirdh/jitniriiiiis  occupy  the 
gamo  compartment.  The  plates  of  the  second  and 
third  rings  either  are  flat,  the  general  curvature  excepted,  or  they  show 
some  inclination  to  forming  faces  of  attachment  for  partition  walls.  The 
four  plates  of  the  upper  ring  constitute  the  upper  end  of  the  anal  tube, 
which  generally  has  a  quadrangular  opening.  Arms  robiust  throughout, 
closely  folded,  and  composed,  from  the  second  or  third  plate  up,  of  two 
rows  of  transverse  pieces.  The  partitions  by  which  they  are  separated 
rarely  extend  up  higher  than  to  one  third  the  length  of  the  arms.  Column 
round  ;  the  axial  c  inal  of  medium  size  and  pentangular. 

Dis/ributio)).  —  The  greatest  number  of  species  occurs  in  tlie  Upper  Silu- 
rian of  Gotland,  and  there  arc  one  or  two  at  Dudley,  England,     llie  genus 
is  represented  in  America  by  four  species  in  the  Nir.garii  group. 
Callicriiius  costatus  (Hisinger)  is  the  type  of  the  genus. 


CALYl-rOCKlNin^K. 


355 


Itemarks.  —  CaUicrmun  is  probably  the  forerunner  of  Eiirn/i/j)fi)pf!niis ;  it 
is  built  on  the  suniu  plan,  but  its  family  cliaractcs  wuru  not, as  yet,  .so  biglily 
difl'erentiuted  as  in  that  genus. 


. 


Calliorinus  Beaohleri  w.  and  Si-. 
Plate  LXXXni.  Fiffs.  l^u,  b. 

1892.     W.  aud  Sp. ;  Aiiicr.  Geologist,  Vol.  X.     Sept.,  p.  140. 

The  calyx  Im.s  the  usual  for.n  of  the  genus.  Its  height  tn  the  base  of  the 
tube  one  fourth  greater  than  the  width  at  the  top  of  the  dor.sal  cup;  the 
height  of  the  cup  11  nun.,  that  of  the  ventral  di.xk  Ki  unii.,  and  the  leuf^lli  of 
the  partition  walls  Sunn.  I)or.sal  cup  broatlly  truncated  at  the  ba.^e;  the 
sides  almost  straight,  gradually  expanding  upwards.  The  radials  aud  costals 
at  the  surface  .sharply  keel-shaped,  especially  the  former,  and  the  angularity 
continued  upon  the  distichal.s,  but  without  attaining  the  prominence  that  it 
lias  at  the  lower  plates ;  the  first  interbrachials  slightly  convex,  with  a  small 
tubercle  in  the  centre. 

Ba.sab:  .small  and  nearly  of  the  .same  size,  forming  a  concavity  which  is 
rather  small  and  shallow  for  the  genus.  Radials  near  the  upper  end  lully  as 
wide  as  long,  and  twice  na  wide  as  ai  the  lower  part,  which  curves  gently 
inward  to  meet  the  basals.  First  costals  twice  as  wide  as  long ;  the  second, 
which  are  longer  and  wider,  rarely  truncated  by  the  interdistiehal.  First 
disticlials  twice  as  large  as  the  .second,  and  but  little  smaller  than  tlit;  upper 
costals.  The  palmars  .small  and  pentangular.  First  interbrachials  longer 
than  wide,  a  little  smaller  than  the  radials ;  the  two  above  together  nearly 
twice  as  wide  as  the  first,  their  upper  ends  rising  to  the  height  of  the 
second  or  third  arm  plates.  luterdistichals  but  little  smaller  than  the  upper 
interbrachials,  and  projecting  upward  in  a  similar  manner.  Ventral  di.sk 
conical,  its  sides  convex.  Tiie  ten  plates  which  rest  upon  the  interbrachials 
and  interdistichals.  respectively,  and  form  the  compartments  for  the  recep- 
tion of  a  pair  of  arm.s.  are  twice  as  high  as  the  ten  intervening  ones,  which 
rest  against  the  sloping  upper  faces  of  the  palmar.s.  There  are  in  all  twenty 
])artitions  around  the  disk,  and  each  arm  occupies  a  separate  compartment. 
The  partition  walls  are  moderately  thick,  and  slightly  grooved  along  their 
outer  faces.  The  ten  larger  ones  ri.se  to  a  level  with  the  upper  end  of  the 
first  ring  of  plates  in  the  disk,  of  which  they  form  wing-like  extensions ; 
they  are  sabre-shaped  and  pointed  at  the  ends.     The  second  ring  of  the  disk 


1  I 


t 


356 


THE  CRINOIDKA  CAMERATA  OF  NORTH  AMERICA. 


conniHts  uf  fuur  plates,  which  arc  much  nnrruwcr  at  the  top  tliiin  nt  the 
bottom,  and  two  of  them  are  narrower  tlian  the  others.  ConHtriiction  ol' the 
anal  tube,  itn  length,  and  the  structure  of  tlu'  arms  unknown. 

Horizon  and  Loealiti/.  —  Niagara  group ;  St.  Paul,  Ind. 

Ti/pc  in  the  collection  of  Wachsnuith  and  Springer. 

Rinutrks.  —  The  unique  »<pecimen  from  which  the  above  description  is 
made,  was  discovered  by  Mr.  Charles  S.  Beachler,  a  very  enthusiastic  collec- 
tor, in  whose  honor  the  species  is  named.  He  has  since  found  u  second 
specimen  at  the  same  locality. 


V 


Calliorinus  aoanthinus  Hi.nuikueuu. 

Piatr  LXXXIII.  Fig.  IS. 

1890.     UiNorKiiKRG  ;  Aniinls  N.  York  Acad.  Sci.,  Vol.  V.,  p.  302,  Plate  3,  Figs.  1  anti  lo. 

The  speoiinons  from  which  this  species  was  described  are  quite  fragment- 
ary, only  showing  portions  of  the  dorsal  cup,  and  notliing  of  its  super- 
striicture,  but  enough  is  seen  to  indicate  that  the  species  i^  unlike  any  other 
hL-retofore  described.  The  dorsal  cup  evidently  was  very  short,  shorter  even 
than  represented  in  Ringueberg's  restored  figure  in  the  Annals,  Tlate  3, 
P'ig.  1,  the  lower  ends  broadly  tr\incated.  and  almost  as  wide  at  the  bottom 
.i-<  at  tlio  top.  The  cup  rests  upon  the  niedi.in  part  of  t!ie  large  radials;  the 
lower  end  of  the  plates  curves  inward  to  meet  the  four  basals,  and  the  upper 
end  abruptly  upwanls. 

The  biisals,  together  with  the  lower  part  of  the  radials,  form  a  deep 
ponnipetalous  coneavity,  which  at  the  inner  side  of  the  calyx  is  represented 
by  a  short  cone,  rounded  at  the  upper  end.  First  costals  twice  as  wide 
as  long,  tiic  suture  lines  convex ;  the  second  a  little  longer,  their  sloping 
upper  faces  at  right  angles.  The  first  distichals  in  contact  laterally,  some- 
what smaller  than  the  upper  costals,  wider  than  long,  the  upper  face  con- 
cave;  the  secoi)  .  much  smaller,  and  the  arm-bearing  palmars  smaller  still. 
First  interhrsjhials  almost  as  large  as  the  radials,  a  little  longer  than  wide, 
subrotundrite  in  outline;  the  two  plates  above  elongate,  and  togoiher  much 
smaller  'Jian  the  first.  The  interdistichal  very  small,  resting  within  a  notch 
fornv.d  by  the  first  distichals.  The  faces  suj)porting  the  partition  walls 
projecting  considerably  over  those  supporting  the  arms.  The  axillary  costals 
and  first  interbrachials  u  o  ex;<?!i;led  into  long,  rather  sharp  .spines,  proceed- 
ing from  the  middle  of  the  plates  and  oK-ccted  obliquely  upward.     In  addi- 


I 


^^m- 


t 


CALYITOCRINID^E. 


35( 


'* 


ion  to  the  npinoH,  the  plntes  have  strong  ridges  or  angular  protnberanceB 
pa.s8ing  out  to  the  sideM,  wliere  tliey  meet  witii  8iniilar  ridges  f'roui  the 
phitfs  below.  The  rudials  have  six  such  ridges,  one  proceeding  to  the  (irs» 
costais,  one  to  the  busals,  two  conimunicato  with  those  of  thi-  interbnichials, 
and  the  two  remaining  ones,  which  form  a  well  defined  pentagon  at  tlie 
lower  margin  of  the  cup,  pass  out  to  the  adjacent  radials.  The  smaller 
plates  in  the  upper  part  of  thi  dorsal  cup  are  convex,  and  slightly  angular 
in  the  middle. 

Horizon  and  Localltij.  —  I^ower  limestone  of  the  Niagara  group.  Lock- 
port,  N.  Y. 

Tjijye  in  the  collection  of  Dr.  E.  N.  S.  Ringuebcrg. 

licmarkn.  —  Dift'ering  from  all  other  American  species  in  the  depressed 
form  of  the  dorsal  cu|),  the  surface  markings  of  the  plates,  and  in  the  num- 
ber, form,  and  direction  of  their  spines. 


,i 


Calliorinus  oornutus  Ham.. 
Plate  LXXXIII.  Fir/s.  15, 16, 17. 

lSfi7.     Kueali/pheriiiHf  rnr,iii/n.i—  IIai.i.;  20iIi  Kcp.  N.  Y,  Sliitn  Cal).  Xnl    Hist  ,  p.  'M2.  Plntr  11,  Y'lgt. 

S',  !•,  10. 
1S82.     Eiieiili/plocriimt  curiiiiluf  —  II.  I'.  WiiiniKLi)  ;    (icul   ltc|i.  Wi^^.,  Vol.  IV.,  p.  2S5,  Plate  10,  Fig.s. 

5-S. 
18S5.     (?)  /iwaljfptorriHH)  eorHntiu  —  W.  aiiil  S.  ;  Rcvisiim  rnlirnoi-.,  I'lirt  111  ,  p.  1S3. 

Syii.  Eiiculiiplnrrinas  roriiu/in,  var.  exi-araliif  IUli,  ;  20lli  Ufp.  N.  V.  estate  Cab.  Nnt.  Hist.,  p.  322, 

riatc  11,  Figs.  0,  7. 

Calyx,  as  seen  from  intern.-il  casts,  more  than  twice  as  wide  as  high,  dor-ai 
cup  broadly  truncated,  and  enorinou.sly  excavated  at  the  bottom,  the  sides  but 
very  slightly  expanding  upwards,  being  almost  vertical.  The  t-xcavation  at 
tlie  bottom  extends  to  nearly  the  full  width  of  the  cup,  and  to  two  thirds  its 
height;  the  circumference  is  sharply  pentangular  with  straight  or  sliglitly 
re-entering  sides,  the  inner  face  grooved  toward  the  angles,  which  are 
directed  radially.  The  arrangement  of  the  plates  is  rarely  seen  upon  the 
internal  cast-!,  and  not  much  better  in  the  gutta  pcrcha  impressions  from 
the  exterior.  In  the  latter,  however,  it  appears  that  the  middle  of  each 
radial  bears  a  long  spine,  which  pa.><si's  outward  and  slightly  upward,  .tml 
occupies  the  lower  margin  of  the  cup.  From  each  side  of  the.se  spines, 
strong  ridges  proceed  to  the  np])er  lateral  margins  of  the  plnte.s,  which  meet 
with  similar  ridges  from  the  interbraehials.  A  .'<omewhat  larger  ridge  runs 
to  the  costais,  where  it  divides  and  sends  a  branch  to  the  distichals.     From 


ii#>e..*ifc-' •''■»,:; 


a58 


TIIK  CRINOIDKA   CAMKRATA  OK   NOKTH   AMKRICA. 


tlio  lower  Hide  of  the  Hpine  tliere  !«  but  one  ridge,  wliich  leads  to  the  biiHalH. 
The  ridges  upon  the  first  inti-rbrachiiils  cuhuiiuite  in  a  sharp  node  in  the 
centre. 

Basals  compuratively  small,  occupying  but  half  tiie  deplli  of  tlie  con- 
cavity. Kadials  very  large,  the  lower  half  curving  abruptly  inward,  and 
loriuing  a  sharp  edge  upon  which  the  cup  rests.  Costals  very  t<uiall,  tiic 
two  together  less  than  half  the  ."ize  of  the  radials  ;  the  first  from  two  to 
three  times  as  wide  as  long  ;  the  second  a  very  little  higher  and  truncated  ut 
the  top.  Distichals,  palmars,  and  interdistichals  very  small ;  the  first  in tcr- 
brachial  unusually  large,  and  as  wide  as  long.  Ventral  disk  stout,  and  to 
the  base  of  the  tube  twice  as  high  a.s  the  dorsal  cup  ;  the  sides  rising  verti- 
cally to  the  top  of  the  trigonal  plate  of  the  first  ring,  whence  they  slope 
slightly  to  the  summit  of  the  ten  larger  ones,  and  more  rapidly  to  the  tube, 
which  near  its  base  is  moderately  thick.  The  ten  larger  plates  of  the  first 
ring  are  longer  than  the  whole  dorsal  cup,  the  intervening  trigonal  ones  but 
half  as  long.  The  former,  as  seen  from  gutta  percha  impressions,  have  long 
spiniform  appendages,  which  probably  reseml)led  those  of  Cdlllrriiiiis  miiixhi- 
.sw((Vw(^»  Angelin  ( Icono<fr.  Plate  28,  Fig.  14);  the}' are  a  little  compressed 
at  the  sides,  and  are  directed  upwards  and  outwards.  The  trigonal  pieces 
also  rise  into  spiniform  partitions,  but  these  are  shorter  and  smaller  gener- 
ally.    Structure  of  the  arms  unknown. 

Ilorizon  and  Ijiwdliti/.  —  Niagara  group  ;  Racine,  Wise,  and  Chicago,  Ills. 

Tf/pes  in  the  N.  Y.  State  Cabinet  of  Natural  History  rt  Albany. 

licntiirks.  — The  large  collections  of  Mr.  Thomas  A.  (Jreene  of  iMilwaukeo, 
and  Mr.  W.  {'.  Kgan  of  Cliicago,  contain  a  few  specimens  in  which  the  dor- 
sal cup  is  unusually  expanded  at  the  arm  bases,  less  broadly  truncated  at 
the  bottom,  and  the  first  costals  somewhat  larger;  while  otherwise  agreeing 
with  the  rest  of  the  specimens.  These  specimens  do  not  agree  with  C.  vor- 
nutiin,  var.  ('3-t'nr((tits  Hall,  which  was  not  accepted  by  Whitfield,  and  we  think 
that  both  these  forms  may  be  regarded  as  variations  of  C  conuttus. 


(?)  Calliorinus  ramifer  v.  Kohmku. 

1S60.     EuetilDploeriimt  ramifrr —  Rokukh  Siliir.  Fiiuiiii  West.  Teiin.,  p.  51,  Plato  4,  Figs.  4fl,  4,  e, 
I">S.J.     Eudili/iilorriHHt  rimifir  —  W.  and  Sp. :    Ui'visiim  I'alivncr.,  Part  111.,  p.  IIU. 

This  species  is  only  known  from  the  general  form  of  its  dorsal  cup,  and 
tliere  is  some  doubt  wiietliei'  it  should  be  referred  to  CuUirfinus  or  to  a  new 
genus.     It  differs  from  the  other  species  of  that  genus  in  the  size  of  its  bas- 


CALYPTOCBIXIDi^t:. 


369 


nl«,  which  aro  Iiiryely  rcpreHented  at  the  oiitor  walls  of  tho  dorsiil  cup ;  inoro- 
ovor  tlio  uricMitiitiuii  of  tlio  puntiingiihir  basal  concavity  i8  revurwud,  its  angles 
being  directi'd  intermdially,  wliilu  tiioy  are  radial  in  C.  cornutun  and  other 
spocioH.  Dorsal  cup  nearly  as  high  as  wide,  the  base  broadly  truncated,  its 
lower  margin  a  little  projecting  laterally  and  Ibrniing  a  sharp  edge  ;  the 
sides  gently  curving  to  near  the  top,  where  they  slightly  contract.  The 
suture  lines  are  not  shown  in  lloeiner's  type,  but  we  can  see  from  a  fragmen- 
tary specimen  in  our  own  collection  that  the  basals  are  very  irregular ;  three 
of  them  are  quadrangular,  tho  fourth  pentangular  and  larger,  the  latter 
broadly  truncated  and  supporting  a  radial,  which  is  smaller  than  the  others 
and  slightly  convex  at  the  lower  face.  The  other  three  basals,  which  rest 
each  one  between  two  radials,  are  distinctly  angular  below.  First  costals 
(|uadrangular,  once  and  a  half  as  wide  as  long  ;  tho  second  considerably 
larger  and  pontangidar,  the  disticlmls  arching  over  its  ujjper  angle.  First 
interbrachial  largo,  decagonal,  almost  as  wide  as  long.  The  platos  thin,  and. 
so  far  as  observed,  wiihout  surface  markings,  except  ob.scure  angularities  fol- 
lowing the  median  lines  of  the  radial.<3  and  brachials,  and  a  small  conical 
elevation  within  the  middle  of  the  first  interbrachial. 

Horizon  and  Lom/I'i).  —  Niagara  group  ;  Wayne  and  Decatur  Cos.,  Tenn. 

Ti/pe  in  the  Mineralogical  Museum,  at  Breslau,  Germany. 

liemarks.  —  If  this  is  a  true  Cdllicriiitis,  it  differs  from  all  the  other  species 
of  this  country,  as  well  as  of  Europe,  in  the  large  size  of  its  basals,  which  in 
no  other  species  are  exposed  along  the  sides  of  the  cup. 


■jmrnms-^:^  ctg^-^'-^ 


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